cpython-lru_cache-weakref: Modules/mathmodule.c annotate

annotate Modules/mathmodule.c @ 60008:0dfd62076ded

author	Benjamin Peterson <benjamin@python.org>
date	Thu, 25 Mar 2010 01:11:10 +0000
parents	9b9adc42c73a
children	cab14be0ada1

rev	line source
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	1 /* Math module -- standard C math library functions, pi and e */
fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	2
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	3 /* Here are some comments from Tim Peters, extracted from the
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	4 discussion attached to http://bugs.python.org/issue1640. They
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	5 describe the general aims of the math module with respect to
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	6 special values, IEEE-754 floating-point exceptions, and Python
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	7 exceptions.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	8
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	9 These are the "spirit of 754" rules:
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	10
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	11 1. If the mathematical result is a real number, but of magnitude too
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	12 large to approximate by a machine float, overflow is signaled and the
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	13 result is an infinity (with the appropriate sign).
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	14
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	15 2. If the mathematical result is a real number, but of magnitude too
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	16 small to approximate by a machine float, underflow is signaled and the
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	17 result is a zero (with the appropriate sign).
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	18
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	19 3. At a singularity (a value x such that the limit of f(y) as y
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	20 approaches x exists and is an infinity), "divide by zero" is signaled
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	21 and the result is an infinity (with the appropriate sign). This is
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	22 complicated a little by that the left-side and right-side limits may
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	23 not be the same; e.g., 1/x approaches +inf or -inf as x approaches 0
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	24 from the positive or negative directions. In that specific case, the
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	25 sign of the zero determines the result of 1/0.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	26
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	27 4. At a point where a function has no defined result in the extended
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	28 reals (i.e., the reals plus an infinity or two), invalid operation is
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	29 signaled and a NaN is returned.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	30
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	31 And these are what Python has historically /tried/ to do (but not
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	32 always successfully, as platform libm behavior varies a lot):
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	33
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	34 For #1, raise OverflowError.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	35
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	36 For #2, return a zero (with the appropriate sign if that happens by
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	37 accident ;-)).
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	38
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	39 For #3 and #4, raise ValueError. It may have made sense to raise
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	40 Python's ZeroDivisionError in #3, but historically that's only been
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	41 raised for division by zero and mod by zero.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	42
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	43 */
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	44
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	45 /*
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	46 In general, on an IEEE-754 platform the aim is to follow the C99
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	47 standard, including Annex 'F', whenever possible. Where the
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	48 standard recommends raising the 'divide-by-zero' or 'invalid'
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	49 floating-point exceptions, Python should raise a ValueError. Where
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	50 the standard recommends raising 'overflow', Python should raise an
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	51 OverflowError. In all other circumstances a value should be
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	52 returned.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	53 */
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	54
4635 49745ddb4f69 Renamed Barry Warsaw <barry@python.org> parents: 4503 diff changeset	55 #include "Python.h"
57758 b45ca11b9a3e Merged revisions 76861 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57660 diff changeset	56 #include "_math.h"
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	57
44943 6547be11f443 Merged revisions 60245-60277 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44499 diff changeset	58 #ifdef _OSF_SOURCE
6547be11f443 Merged revisions 60245-60277 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44499 diff changeset	59 /* OSF1 5.1 doesn't make this available with XOPEN_SOURCE_EXTENDED defined */
6547be11f443 Merged revisions 60245-60277 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44499 diff changeset	60 extern double copysign(double, double);
6547be11f443 Merged revisions 60245-60277 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44499 diff changeset	61 #endif
6547be11f443 Merged revisions 60245-60277 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44499 diff changeset	62
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	63 /*
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	64 sin(pi*x), giving accurate results for all finite x (especially x
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	65 integral or close to an integer). This is here for use in the
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	66 reflection formula for the gamma function. It conforms to IEEE
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	67 754-2008 for finite arguments, but not for infinities or nans.
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	68 */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	69
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	70 static const double pi = 3.141592653589793238462643383279502884197;
57770 1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	71 static const double sqrtpi = 1.772453850905516027298167483341145182798;
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	72
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	73 static double
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	74 sinpi(double x)
498 56bb1067a880 Improve error handling. Guido van Rossum <guido@python.org> parents: 438 diff changeset	75 {
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	76 double y, r;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	77 int n;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	78 /* this function should only ever be called for finite arguments */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	79 assert(Py_IS_FINITE(x));
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	80 y = fmod(fabs(x), 2.0);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	81 n = (int)round(2.0*y);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	82 assert(0 <= n && n <= 4);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	83 switch (n) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	84 case 0:
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	85 r = sin(pi*y);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	86 break;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	87 case 1:
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	88 r = cos(pi*(y-0.5));
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	89 break;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	90 case 2:
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	91 /* N.B. -sin(pi(y-1.0)) is not* equivalent: it would give
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	92 -0.0 instead of 0.0 when y == 1.0. */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	93 r = sin(pi*(1.0-y));
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	94 break;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	95 case 3:
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	96 r = -cos(pi*(y-1.5));
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	97 break;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	98 case 4:
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	99 r = sin(pi*(y-2.0));
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	100 break;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	101 default:
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	102 assert(0); /* should never get here */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	103 r = -1.23e200; /* silence gcc warning */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	104 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	105 return copysign(1.0, x)*r;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	106 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	107
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	108 /* Implementation of the real gamma function. In extensive but non-exhaustive
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	109 random tests, this function proved accurate to within <= 10 ulps across the
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	110 entire float domain. Note that accuracy may depend on the quality of the
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	111 system math functions, the pow function in particular. Special cases
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	112 follow C99 annex F. The parameters and method are tailored to platforms
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	113 whose double format is the IEEE 754 binary64 format.
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	114
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	115 Method: for x > 0.0 we use the Lanczos approximation with parameters N=13
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	116 and g=6.024680040776729583740234375; these parameters are amongst those
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	117 used by the Boost library. Following Boost (again), we re-express the
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	118 Lanczos sum as a rational function, and compute it that way. The
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	119 coefficients below were computed independently using MPFR, and have been
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	120 double-checked against the coefficients in the Boost source code.
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	121
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	122 For x < 0.0 we use the reflection formula.
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	123
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	124 There's one minor tweak that deserves explanation: Lanczos' formula for
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	125 Gamma(x) involves computing pow(x+g-0.5, x-0.5) / exp(x+g-0.5). For many x
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	126 values, x+g-0.5 can be represented exactly. However, in cases where it
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	127 can't be represented exactly the small error in x+g-0.5 can be magnified
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	128 significantly by the pow and exp calls, especially for large x. A cheap
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	129 correction is to multiply by (1 + e*g/(x+g-0.5)), where e is the error
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	130 involved in the computation of x+g-0.5 (that is, e = computed value of
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	131 x+g-0.5 - exact value of x+g-0.5). Here's the proof:
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	132
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	133 Correction factor
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	134 -----------------
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	135 Write x+g-0.5 = y-e, where y is exactly representable as an IEEE 754
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	136 double, and e is tiny. Then:
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	137
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	138 pow(x+g-0.5,x-0.5)/exp(x+g-0.5) = pow(y-e, x-0.5)/exp(y-e)
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	139 = pow(y, x-0.5)/exp(y) * C,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	140
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	141 where the correction_factor C is given by
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	142
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	143 C = pow(1-e/y, x-0.5) * exp(e)
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	144
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	145 Since e is tiny, pow(1-e/y, x-0.5) ~ 1-(x-0.5)*e/y, and exp(x) ~ 1+e, so:
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	146
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	147 C ~ (1-(x-0.5)e/y) (1+e) ~ 1 + e*(y-(x-0.5))/y
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	148
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	149 But y-(x-0.5) = g+e, and g+e ~ g. So we get C ~ 1 + e*g/y, and
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	150
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	151 pow(x+g-0.5,x-0.5)/exp(x+g-0.5) ~ pow(y, x-0.5)/exp(y) * (1 + e*g/y),
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	152
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	153 Note that for accuracy, when computing r*C it's better to do
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	154
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	155 r + eg/yr;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	156
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	157 than
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	158
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	159 r * (1 + e*g/y);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	160
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	161 since the addition in the latter throws away most of the bits of
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	162 information in e*g/y.
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	163 */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	164
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	165 #define LANCZOS_N 13
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	166 static const double lanczos_g = 6.024680040776729583740234375;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	167 static const double lanczos_g_minus_half = 5.524680040776729583740234375;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	168 static const double lanczos_num_coeffs[LANCZOS_N] = {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	169 23531376880.410759688572007674451636754734846804940,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	170 42919803642.649098768957899047001988850926355848959,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	171 35711959237.355668049440185451547166705960488635843,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	172 17921034426.037209699919755754458931112671403265390,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	173 6039542586.3520280050642916443072979210699388420708,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	174 1439720407.3117216736632230727949123939715485786772,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	175 248874557.86205415651146038641322942321632125127801,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	176 31426415.585400194380614231628318205362874684987640,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	177 2876370.6289353724412254090516208496135991145378768,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	178 186056.26539522349504029498971604569928220784236328,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	179 8071.6720023658162106380029022722506138218516325024,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	180 210.82427775157934587250973392071336271166969580291,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	181 2.5066282746310002701649081771338373386264310793408
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	182 };
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	183
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	184 /* denominator is x(x+1)...(x+LANCZOS_N-2) /
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	185 static const double lanczos_den_coeffs[LANCZOS_N] = {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	186 0.0, 39916800.0, 120543840.0, 150917976.0, 105258076.0, 45995730.0,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	187 13339535.0, 2637558.0, 357423.0, 32670.0, 1925.0, 66.0, 1.0};
19750 35b6a1d0b1e0 Rework the way we try to check for libm overflow, given that C99 no longer Tim Peters <tim.peters@gmail.com> parents: 19730 diff changeset	188
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	189 /* gamma values for small positive integers, 1 though NGAMMA_INTEGRAL */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	190 #define NGAMMA_INTEGRAL 23
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	191 static const double gamma_integral[NGAMMA_INTEGRAL] = {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	192 1.0, 1.0, 2.0, 6.0, 24.0, 120.0, 720.0, 5040.0, 40320.0, 362880.0,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	193 3628800.0, 39916800.0, 479001600.0, 6227020800.0, 87178291200.0,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	194 1307674368000.0, 20922789888000.0, 355687428096000.0,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	195 6402373705728000.0, 121645100408832000.0, 2432902008176640000.0,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	196 51090942171709440000.0, 1124000727777607680000.0,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	197 };
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	198
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	199 /* Lanczos' sum L_g(x), for positive x */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	200
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	201 static double
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	202 lanczos_sum(double x)
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	203 {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	204 double num = 0.0, den = 0.0;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	205 int i;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	206 assert(x > 0.0);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	207 /* evaluate the rational function lanczos_sum(x). For large
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	208 x, the obvious algorithm risks overflow, so we instead
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	209 rescale the denominator and numerator of the rational
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	210 function by x**(1-LANCZOS_N) and treat this as a
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	211 rational function in 1/x. This also reduces the error for
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	212 larger x values. The choice of cutoff point (5.0 below) is
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	213 somewhat arbitrary; in tests, smaller cutoff values than
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	214 this resulted in lower accuracy. */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	215 if (x < 5.0) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	216 for (i = LANCZOS_N; --i >= 0; ) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	217 num = num * x + lanczos_num_coeffs[i];
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	218 den = den * x + lanczos_den_coeffs[i];
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	219 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	220 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	221 else {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	222 for (i = 0; i < LANCZOS_N; i++) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	223 num = num / x + lanczos_num_coeffs[i];
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	224 den = den / x + lanczos_den_coeffs[i];
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	225 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	226 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	227 return num/den;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	228 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	229
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	230 static double
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	231 m_tgamma(double x)
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	232 {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	233 double absx, r, y, z, sqrtpow;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	234
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	235 /* special cases */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	236 if (!Py_IS_FINITE(x)) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	237 if (Py_IS_NAN(x) \|\| x > 0.0)
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	238 return x; /* tgamma(nan) = nan, tgamma(inf) = inf */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	239 else {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	240 errno = EDOM;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	241 return Py_NAN; /* tgamma(-inf) = nan, invalid */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	242 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	243 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	244 if (x == 0.0) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	245 errno = EDOM;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	246 return 1.0/x; /* tgamma(+-0.0) = +-inf, divide-by-zero */
15170 09c7ac188ce2 Stop raising OverflowError on underflows reported by libm (errno==ERANGE and Tim Peters <tim.peters@gmail.com> parents: 14616 diff changeset	247 }
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	248
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	249 /* integer arguments */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	250 if (x == floor(x)) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	251 if (x < 0.0) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	252 errno = EDOM; /* tgamma(n) = nan, invalid for */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	253 return Py_NAN; /* negative integers n */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	254 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	255 if (x <= NGAMMA_INTEGRAL)
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	256 return gamma_integral[(int)x - 1];
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	257 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	258 absx = fabs(x);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	259
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	260 /* tiny arguments: tgamma(x) ~ 1/x for x near 0 */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	261 if (absx < 1e-20) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	262 r = 1.0/x;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	263 if (Py_IS_INFINITY(r))
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	264 errno = ERANGE;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	265 return r;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	266 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	267
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	268 /* large arguments: assuming IEEE 754 doubles, tgamma(x) overflows for
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	269 x > 200, and underflows to +-0.0 for x < -200, not a negative
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	270 integer. */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	271 if (absx > 200.0) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	272 if (x < 0.0) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	273 return 0.0/sinpi(x);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	274 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	275 else {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	276 errno = ERANGE;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	277 return Py_HUGE_VAL;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	278 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	279 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	280
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	281 y = absx + lanczos_g_minus_half;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	282 /* compute error in sum */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	283 if (absx > lanczos_g_minus_half) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	284 /* note: the correction can be foiled by an optimizing
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	285 compiler that (incorrectly) thinks that an expression like
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	286 a + b - a - b can be optimized to 0.0. This shouldn't
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	287 happen in a standards-conforming compiler. */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	288 double q = y - absx;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	289 z = q - lanczos_g_minus_half;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	290 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	291 else {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	292 double q = y - lanczos_g_minus_half;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	293 z = q - absx;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	294 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	295 z = z * lanczos_g / y;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	296 if (x < 0.0) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	297 r = -pi / sinpi(absx) / absx * exp(y) / lanczos_sum(absx);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	298 r -= z * r;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	299 if (absx < 140.0) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	300 r /= pow(y, absx - 0.5);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	301 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	302 else {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	303 sqrtpow = pow(y, absx / 2.0 - 0.25);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	304 r /= sqrtpow;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	305 r /= sqrtpow;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	306 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	307 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	308 else {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	309 r = lanczos_sum(absx) / exp(y);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	310 r += z * r;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	311 if (absx < 140.0) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	312 r *= pow(y, absx - 0.5);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	313 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	314 else {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	315 sqrtpow = pow(y, absx / 2.0 - 0.25);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	316 r *= sqrtpow;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	317 r *= sqrtpow;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	318 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	319 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	320 if (Py_IS_INFINITY(r))
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	321 errno = ERANGE;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	322 return r;
498 56bb1067a880 Improve error handling. Guido van Rossum <guido@python.org> parents: 438 diff changeset	323 }
56bb1067a880 Improve error handling. Guido van Rossum <guido@python.org> parents: 438 diff changeset	324
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	325 /*
57660 7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	326 lgamma: natural log of the absolute value of the Gamma function.
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	327 For large arguments, Lanczos' formula works extremely well here.
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	328 */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	329
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	330 static double
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	331 m_lgamma(double x)
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	332 {
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	333 double r, absx;
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	334
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	335 /* special cases */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	336 if (!Py_IS_FINITE(x)) {
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	337 if (Py_IS_NAN(x))
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	338 return x; /* lgamma(nan) = nan */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	339 else
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	340 return Py_HUGE_VAL; /* lgamma(+-inf) = +inf */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	341 }
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	342
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	343 /* integer arguments */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	344 if (x == floor(x) && x <= 2.0) {
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	345 if (x <= 0.0) {
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	346 errno = EDOM; /* lgamma(n) = inf, divide-by-zero for */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	347 return Py_HUGE_VAL; /* integers n <= 0 */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	348 }
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	349 else {
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	350 return 0.0; /* lgamma(1) = lgamma(2) = 0.0 */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	351 }
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	352 }
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	353
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	354 absx = fabs(x);
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	355 /* tiny arguments: lgamma(x) ~ -log(fabs(x)) for small x */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	356 if (absx < 1e-20)
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	357 return -log(absx);
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	358
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	359 /* Lanczos' formula */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	360 if (x > 0.0) {
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	361 /* we could save a fraction of a ulp in accuracy by having a
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	362 second set of numerator coefficients for lanczos_sum that
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	363 absorbed the exp(-lanczos_g) term, and throwing out the
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	364 lanczos_g subtraction below; it's probably not worth it. */
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	365 r = log(lanczos_sum(x)) - lanczos_g +
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	366 (x-0.5)*(log(x+lanczos_g-0.5)-1);
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	367 }
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	368 else {
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	369 r = log(pi) - log(fabs(sinpi(absx))) - log(absx) -
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	370 (log(lanczos_sum(absx)) - lanczos_g +
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	371 (absx-0.5)*(log(absx+lanczos_g-0.5)-1));
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	372 }
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	373 if (Py_IS_INFINITY(r))
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	374 errno = ERANGE;
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	375 return r;
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	376 }
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	377
57770 1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	378 /*
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	379 Implementations of the error function erf(x) and the complementary error
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	380 function erfc(x).
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	381
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	382 Method: following 'Numerical Recipes' by Flannery, Press et. al. (2nd ed.,
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	383 Cambridge University Press), we use a series approximation for erf for
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	384 small x, and a continued fraction approximation for erfc(x) for larger x;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	385 combined with the relations erf(-x) = -erf(x) and erfc(x) = 1.0 - erf(x),
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	386 this gives us erf(x) and erfc(x) for all x.
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	387
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	388 The series expansion used is:
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	389
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	390 erf(x) = xexp(-xx)/sqrt(pi) * [
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	391 2/1 + 4/3 x2 + 8/15 x4 + 16/105 x**6 + ...]
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	392
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	393 The coefficient of x(2k-2) here is 4kfactorial(k)/factorial(2k).
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	394 This series converges well for smallish x, but slowly for larger x.
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	395
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	396 The continued fraction expansion used is:
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	397
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	398 erfc(x) = xexp(-xx)/sqrt(pi) * [1/(0.5 + x2 -) 0.5/(2.5 + x2 - )
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	399 3.0/(4.5 + x2 - ) 7.5/(6.5 + x2 - ) ...]
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	400
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	401 after the first term, the general term has the form:
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	402
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	403 k(k-0.5)/(2k+0.5 + x**2 - ...).
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	404
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	405 This expansion converges fast for larger x, but convergence becomes
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	406 infinitely slow as x approaches 0.0. The (somewhat naive) continued
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	407 fraction evaluation algorithm used below also risks overflow for large x;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	408 but for large x, erfc(x) == 0.0 to within machine precision. (For
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	409 example, erfc(30.0) is approximately 2.56e-393).
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	410
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	411 Parameters: use series expansion for abs(x) < ERF_SERIES_CUTOFF and
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	412 continued fraction expansion for ERF_SERIES_CUTOFF <= abs(x) <
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	413 ERFC_CONTFRAC_CUTOFF. ERFC_SERIES_TERMS and ERFC_CONTFRAC_TERMS are the
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	414 numbers of terms to use for the relevant expansions. */
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	415
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	416 #define ERF_SERIES_CUTOFF 1.5
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	417 #define ERF_SERIES_TERMS 25
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	418 #define ERFC_CONTFRAC_CUTOFF 30.0
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	419 #define ERFC_CONTFRAC_TERMS 50
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	420
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	421 /*
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	422 Error function, via power series.
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	423
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	424 Given a finite float x, return an approximation to erf(x).
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	425 Converges reasonably fast for small x.
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	426 */
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	427
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	428 static double
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	429 m_erf_series(double x)
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	430 {
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	431 double x2, acc, fk;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	432 int i;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	433
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	434 x2 = x * x;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	435 acc = 0.0;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	436 fk = (double)ERF_SERIES_TERMS + 0.5;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	437 for (i = 0; i < ERF_SERIES_TERMS; i++) {
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	438 acc = 2.0 + x2 * acc / fk;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	439 fk -= 1.0;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	440 }
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	441 return acc * x * exp(-x2) / sqrtpi;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	442 }
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	443
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	444 /*
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	445 Complementary error function, via continued fraction expansion.
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	446
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	447 Given a positive float x, return an approximation to erfc(x). Converges
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	448 reasonably fast for x large (say, x > 2.0), and should be safe from
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	449 overflow if x and nterms are not too large. On an IEEE 754 machine, with x
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	450 <= 30.0, we're safe up to nterms = 100. For x >= 30.0, erfc(x) is smaller
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	451 than the smallest representable nonzero float. */
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	452
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	453 static double
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	454 m_erfc_contfrac(double x)
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	455 {
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	456 double x2, a, da, p, p_last, q, q_last, b;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	457 int i;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	458
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	459 if (x >= ERFC_CONTFRAC_CUTOFF)
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	460 return 0.0;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	461
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	462 x2 = x*x;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	463 a = 0.0;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	464 da = 0.5;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	465 p = 1.0; p_last = 0.0;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	466 q = da + x2; q_last = 1.0;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	467 for (i = 0; i < ERFC_CONTFRAC_TERMS; i++) {
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	468 double temp;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	469 a += da;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	470 da += 2.0;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	471 b = da + x2;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	472 temp = p; p = bp - ap_last; p_last = temp;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	473 temp = q; q = bq - aq_last; q_last = temp;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	474 }
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	475 return p / q * x * exp(-x2) / sqrtpi;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	476 }
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	477
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	478 /* Error function erf(x), for general x */
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	479
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	480 static double
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	481 m_erf(double x)
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	482 {
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	483 double absx, cf;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	484
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	485 if (Py_IS_NAN(x))
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	486 return x;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	487 absx = fabs(x);
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	488 if (absx < ERF_SERIES_CUTOFF)
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	489 return m_erf_series(x);
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	490 else {
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	491 cf = m_erfc_contfrac(absx);
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	492 return x > 0.0 ? 1.0 - cf : cf - 1.0;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	493 }
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	494 }
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	495
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	496 /* Complementary error function erfc(x), for general x. */
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	497
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	498 static double
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	499 m_erfc(double x)
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	500 {
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	501 double absx, cf;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	502
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	503 if (Py_IS_NAN(x))
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	504 return x;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	505 absx = fabs(x);
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	506 if (absx < ERF_SERIES_CUTOFF)
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	507 return 1.0 - m_erf_series(x);
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	508 else {
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	509 cf = m_erfc_contfrac(absx);
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	510 return x > 0.0 ? cf : 2.0 - cf;
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	511 }
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	512 }
57660 7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	513
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	514 /*
46516 ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	515 wrapper for atan2 that deals directly with special cases before
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	516 delegating to the platform libm for the remaining cases. This
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	517 is necessary to get consistent behaviour across platforms.
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	518 Windows, FreeBSD and alpha Tru64 are amongst platforms that don't
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	519 always follow C99.
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	520 */
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	521
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	522 static double
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	523 m_atan2(double y, double x)
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	524 {
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	525 if (Py_IS_NAN(x) \|\| Py_IS_NAN(y))
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	526 return Py_NAN;
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	527 if (Py_IS_INFINITY(y)) {
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	528 if (Py_IS_INFINITY(x)) {
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	529 if (copysign(1., x) == 1.)
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	530 /* atan2(+-inf, +inf) == +-pi/4 */
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	531 return copysign(0.25*Py_MATH_PI, y);
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	532 else
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	533 /* atan2(+-inf, -inf) == +-pi3/4 /
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	534 return copysign(0.75*Py_MATH_PI, y);
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	535 }
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	536 /* atan2(+-inf, x) == +-pi/2 for finite x */
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	537 return copysign(0.5*Py_MATH_PI, y);
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	538 }
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	539 if (Py_IS_INFINITY(x) \|\| y == 0.) {
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	540 if (copysign(1., x) == 1.)
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	541 /* atan2(+-y, +inf) = atan2(+-0, +x) = +-0. */
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	542 return copysign(0., y);
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	543 else
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	544 /* atan2(+-y, -inf) = atan2(+-0., -x) = +-pi. */
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	545 return copysign(Py_MATH_PI, y);
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	546 }
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	547 return atan2(y, x);
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	548 }
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	549
ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	550 /*
50123 20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	551 Various platforms (Solaris, OpenBSD) do nonstandard things for log(0),
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	552 log(-ve), log(NaN). Here are wrappers for log and log10 that deal with
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	553 special values directly, passing positive non-special values through to
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	554 the system log/log10.
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	555 */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	556
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	557 static double
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	558 m_log(double x)
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	559 {
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	560 if (Py_IS_FINITE(x)) {
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	561 if (x > 0.0)
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	562 return log(x);
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	563 errno = EDOM;
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	564 if (x == 0.0)
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	565 return -Py_HUGE_VAL; /* log(0) = -inf */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	566 else
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	567 return Py_NAN; /* log(-ve) = nan */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	568 }
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	569 else if (Py_IS_NAN(x))
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	570 return x; /* log(nan) = nan */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	571 else if (x > 0.0)
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	572 return x; /* log(inf) = inf */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	573 else {
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	574 errno = EDOM;
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	575 return Py_NAN; /* log(-inf) = nan */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	576 }
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	577 }
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	578
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	579 static double
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	580 m_log10(double x)
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	581 {
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	582 if (Py_IS_FINITE(x)) {
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	583 if (x > 0.0)
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	584 return log10(x);
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	585 errno = EDOM;
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	586 if (x == 0.0)
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	587 return -Py_HUGE_VAL; /* log10(0) = -inf */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	588 else
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	589 return Py_NAN; /* log10(-ve) = nan */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	590 }
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	591 else if (Py_IS_NAN(x))
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	592 return x; /* log10(nan) = nan */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	593 else if (x > 0.0)
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	594 return x; /* log10(inf) = inf */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	595 else {
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	596 errno = EDOM;
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	597 return Py_NAN; /* log10(-inf) = nan */
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	598 }
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	599 }
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	600
20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	601
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	602 /* Call is_error when errno != 0, and where x is the result libm
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	603 * returned. is_error will usually set up an exception and return
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	604 * true (1), but may return false (0) without setting up an exception.
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	605 */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	606 static int
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	607 is_error(double x)
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	608 {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	609 int result = 1; /* presumption of guilt */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	610 assert(errno); /* non-zero errno is a precondition for calling */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	611 if (errno == EDOM)
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	612 PyErr_SetString(PyExc_ValueError, "math domain error");
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	613
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	614 else if (errno == ERANGE) {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	615 /* ANSI C generally requires libm functions to set ERANGE
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	616 * on overflow, but also generally allows them to set
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	617 * ERANGE on underflow too. There's no consistency about
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	618 * the latter across platforms.
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	619 * Alas, C99 never requires that errno be set.
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	620 * Here we suppress the underflow errors (libm functions
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	621 * should return a zero on underflow, and +- HUGE_VAL on
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	622 * overflow, so testing the result for zero suffices to
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	623 * distinguish the cases).
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	624 *
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	625 * On some platforms (Ubuntu/ia64) it seems that errno can be
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	626 * set to ERANGE for subnormal results that do not underflow
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	627 * to zero. So to be safe, we'll ignore ERANGE whenever the
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	628 * function result is less than one in absolute value.
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	629 */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	630 if (fabs(x) < 1.0)
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	631 result = 0;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	632 else
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	633 PyErr_SetString(PyExc_OverflowError,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	634 "math range error");
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	635 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	636 else
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	637 /* Unexpected math error */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	638 PyErr_SetFromErrno(PyExc_ValueError);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	639 return result;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	640 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	641
50123 20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	642 /*
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	643 math_1 is used to wrap a libm function f that takes a double
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	644 arguments and returns a double.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	645
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	646 The error reporting follows these rules, which are designed to do
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	647 the right thing on C89/C99 platforms and IEEE 754/non IEEE 754
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	648 platforms.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	649
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	650 - a NaN result from non-NaN inputs causes ValueError to be raised
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	651 - an infinite result from finite inputs causes OverflowError to be
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	652 raised if can_overflow is 1, or raises ValueError if can_overflow
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	653 is 0.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	654 - if the result is finite and errno == EDOM then ValueError is
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	655 raised
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	656 - if the result is finite and nonzero and errno == ERANGE then
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	657 OverflowError is raised
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	658
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	659 The last rule is used to catch overflow on platforms which follow
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	660 C89 but for which HUGE_VAL is not an infinity.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	661
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	662 For the majority of one-argument functions these rules are enough
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	663 to ensure that Python's functions behave as specified in 'Annex F'
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	664 of the C99 standard, with the 'invalid' and 'divide-by-zero'
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	665 floating-point exceptions mapping to Python's ValueError and the
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	666 'overflow' floating-point exception mapping to OverflowError.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	667 math_1 only works for functions that don't have singularities and
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	668 the possibility of overflow; fortunately, that covers everything we
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	669 care about right now.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	670 */
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	671
4635 49745ddb4f69 Renamed Barry Warsaw <barry@python.org> parents: 4503 diff changeset	672 static PyObject *
44499 31e294d08ce1 Make math.floor and math.ceil return ints instead of floats. Jeffrey Yasskin <jyasskin@gmail.com> parents: 44460 diff changeset	673 math_1_to_whatever(PyObject arg, double (func) (double),
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	674 PyObject (from_double_func) (double),
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	675 int can_overflow)
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	676 {
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	677 double x, r;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	678 x = PyFloat_AsDouble(arg);
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	679 if (x == -1.0 && PyErr_Occurred())
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	680 return NULL;
fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	681 errno = 0;
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	682 PyFPE_START_PROTECT("in math_1", return 0);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	683 r = (*func)(x);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	684 PyFPE_END_PROTECT(r);
46616 3f2117d3271f Make floating-point exception error messages slightly more verbose: in Mark Dickinson <dickinsm@gmail.com> parents: 46516 diff changeset	685 if (Py_IS_NAN(r) && !Py_IS_NAN(x)) {
3f2117d3271f Make floating-point exception error messages slightly more verbose: in Mark Dickinson <dickinsm@gmail.com> parents: 46516 diff changeset	686 PyErr_SetString(PyExc_ValueError,
48331 a6503ae3e19c Quick fix for test_math failures on Solaris 10 buildbot. For future Mark Dickinson <dickinsm@gmail.com> parents: 48326 diff changeset	687 "math domain error"); /* invalid arg */
46616 3f2117d3271f Make floating-point exception error messages slightly more verbose: in Mark Dickinson <dickinsm@gmail.com> parents: 46516 diff changeset	688 return NULL;
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	689 }
46616 3f2117d3271f Make floating-point exception error messages slightly more verbose: in Mark Dickinson <dickinsm@gmail.com> parents: 46516 diff changeset	690 if (Py_IS_INFINITY(r) && Py_IS_FINITE(x)) {
3f2117d3271f Make floating-point exception error messages slightly more verbose: in Mark Dickinson <dickinsm@gmail.com> parents: 46516 diff changeset	691 if (can_overflow)
3f2117d3271f Make floating-point exception error messages slightly more verbose: in Mark Dickinson <dickinsm@gmail.com> parents: 46516 diff changeset	692 PyErr_SetString(PyExc_OverflowError,
48331 a6503ae3e19c Quick fix for test_math failures on Solaris 10 buildbot. For future Mark Dickinson <dickinsm@gmail.com> parents: 48326 diff changeset	693 "math range error"); /* overflow */
46791 8b67685a8bc3 Revert the temporary change in r62624 Mark Dickinson <dickinsm@gmail.com> parents: 46664 diff changeset	694 else
8b67685a8bc3 Revert the temporary change in r62624 Mark Dickinson <dickinsm@gmail.com> parents: 46664 diff changeset	695 PyErr_SetString(PyExc_ValueError,
48331 a6503ae3e19c Quick fix for test_math failures on Solaris 10 buildbot. For future Mark Dickinson <dickinsm@gmail.com> parents: 48326 diff changeset	696 "math domain error"); /* singularity */
46616 3f2117d3271f Make floating-point exception error messages slightly more verbose: in Mark Dickinson <dickinsm@gmail.com> parents: 46516 diff changeset	697 return NULL;
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	698 }
46617 e42fe19ba6fd Whoops. errno should only be tested when the result is finite. Mark Dickinson <dickinsm@gmail.com> parents: 46616 diff changeset	699 if (Py_IS_FINITE(r) && errno && is_error(r))
e42fe19ba6fd Whoops. errno should only be tested when the result is finite. Mark Dickinson <dickinsm@gmail.com> parents: 46616 diff changeset	700 /* this branch unnecessary on most platforms */
15170 09c7ac188ce2 Stop raising OverflowError on underflows reported by libm (errno==ERANGE and Tim Peters <tim.peters@gmail.com> parents: 14616 diff changeset	701 return NULL;
46617 e42fe19ba6fd Whoops. errno should only be tested when the result is finite. Mark Dickinson <dickinsm@gmail.com> parents: 46616 diff changeset	702
e42fe19ba6fd Whoops. errno should only be tested when the result is finite. Mark Dickinson <dickinsm@gmail.com> parents: 46616 diff changeset	703 return (*from_double_func)(r);
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	704 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	705
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	706 /* variant of math_1, to be used when the function being wrapped is known to
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	707 set errno properly (that is, errno = EDOM for invalid or divide-by-zero,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	708 errno = ERANGE for overflow). */
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	709
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	710 static PyObject *
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	711 math_1a(PyObject arg, double (func) (double))
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	712 {
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	713 double x, r;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	714 x = PyFloat_AsDouble(arg);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	715 if (x == -1.0 && PyErr_Occurred())
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	716 return NULL;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	717 errno = 0;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	718 PyFPE_START_PROTECT("in math_1a", return 0);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	719 r = (*func)(x);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	720 PyFPE_END_PROTECT(r);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	721 if (errno && is_error(r))
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	722 return NULL;
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	723 return PyFloat_FromDouble(r);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	724 }
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	725
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	726 /*
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	727 math_2 is used to wrap a libm function f that takes two double
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	728 arguments and returns a double.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	729
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	730 The error reporting follows these rules, which are designed to do
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	731 the right thing on C89/C99 platforms and IEEE 754/non IEEE 754
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	732 platforms.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	733
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	734 - a NaN result from non-NaN inputs causes ValueError to be raised
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	735 - an infinite result from finite inputs causes OverflowError to be
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	736 raised.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	737 - if the result is finite and errno == EDOM then ValueError is
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	738 raised
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	739 - if the result is finite and nonzero and errno == ERANGE then
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	740 OverflowError is raised
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	741
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	742 The last rule is used to catch overflow on platforms which follow
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	743 C89 but for which HUGE_VAL is not an infinity.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	744
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	745 For most two-argument functions (copysign, fmod, hypot, atan2)
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	746 these rules are enough to ensure that Python's functions behave as
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	747 specified in 'Annex F' of the C99 standard, with the 'invalid' and
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	748 'divide-by-zero' floating-point exceptions mapping to Python's
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	749 ValueError and the 'overflow' floating-point exception mapping to
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	750 OverflowError.
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	751 */
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	752
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	753 static PyObject *
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	754 math_1(PyObject arg, double (func) (double), int can_overflow)
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	755 {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	756 return math_1_to_whatever(arg, func, PyFloat_FromDouble, can_overflow);
44499 31e294d08ce1 Make math.floor and math.ceil return ints instead of floats. Jeffrey Yasskin <jyasskin@gmail.com> parents: 44460 diff changeset	757 }
31e294d08ce1 Make math.floor and math.ceil return ints instead of floats. Jeffrey Yasskin <jyasskin@gmail.com> parents: 44460 diff changeset	758
31e294d08ce1 Make math.floor and math.ceil return ints instead of floats. Jeffrey Yasskin <jyasskin@gmail.com> parents: 44460 diff changeset	759 static PyObject *
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	760 math_1_to_int(PyObject arg, double (func) (double), int can_overflow)
44499 31e294d08ce1 Make math.floor and math.ceil return ints instead of floats. Jeffrey Yasskin <jyasskin@gmail.com> parents: 44460 diff changeset	761 {
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	762 return math_1_to_whatever(arg, func, PyLong_FromDouble, can_overflow);
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	763 }
fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	764
4635 49745ddb4f69 Renamed Barry Warsaw <barry@python.org> parents: 4503 diff changeset	765 static PyObject *
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	766 math_2(PyObject args, double (func) (double, double), char *funcname)
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	767 {
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	768 PyObject ox, oy;
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	769 double x, y, r;
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	770 if (! PyArg_UnpackTuple(args, funcname, 2, 2, &ox, &oy))
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	771 return NULL;
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	772 x = PyFloat_AsDouble(ox);
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	773 y = PyFloat_AsDouble(oy);
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	774 if ((x == -1.0 \|\| y == -1.0) && PyErr_Occurred())
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	775 return NULL;
fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	776 errno = 0;
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	777 PyFPE_START_PROTECT("in math_2", return 0);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	778 r = (*func)(x, y);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	779 PyFPE_END_PROTECT(r);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	780 if (Py_IS_NAN(r)) {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	781 if (!Py_IS_NAN(x) && !Py_IS_NAN(y))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	782 errno = EDOM;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	783 else
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	784 errno = 0;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	785 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	786 else if (Py_IS_INFINITY(r)) {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	787 if (Py_IS_FINITE(x) && Py_IS_FINITE(y))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	788 errno = ERANGE;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	789 else
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	790 errno = 0;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	791 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	792 if (errno && is_error(r))
15170 09c7ac188ce2 Stop raising OverflowError on underflows reported by libm (errno==ERANGE and Tim Peters <tim.peters@gmail.com> parents: 14616 diff changeset	793 return NULL;
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	794 else
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	795 return PyFloat_FromDouble(r);
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	796 }
fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	797
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	798 #define FUNC1(funcname, func, can_overflow, docstring) \
13326 24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	799 static PyObject * math_##funcname(PyObject self, PyObject args) { \
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	800 return math_1(args, func, can_overflow); \
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	801 }\
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	802 PyDoc_STRVAR(math_##funcname##_doc, docstring);
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	803
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	804 #define FUNC1A(funcname, func, docstring) \
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	805 static PyObject * math_##funcname(PyObject self, PyObject args) { \
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	806 return math_1a(args, func); \
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	807 }\
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	808 PyDoc_STRVAR(math_##funcname##_doc, docstring);
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	809
13326 24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	810 #define FUNC2(funcname, func, docstring) \
24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	811 static PyObject * math_##funcname(PyObject self, PyObject args) { \
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	812 return math_2(args, func, #funcname); \
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	813 }\
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	814 PyDoc_STRVAR(math_##funcname##_doc, docstring);
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	815
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	816 FUNC1(acos, acos, 0,
19048 e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	817 "acos(x)\n\nReturn the arc cosine (measured in radians) of x.")
57866 9751ddcc1882 Merged revisions 76978 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57808 diff changeset	818 FUNC1(acosh, m_acosh, 0,
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	819 "acosh(x)\n\nReturn the hyperbolic arc cosine (measured in radians) of x.")
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	820 FUNC1(asin, asin, 0,
19048 e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	821 "asin(x)\n\nReturn the arc sine (measured in radians) of x.")
57866 9751ddcc1882 Merged revisions 76978 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57808 diff changeset	822 FUNC1(asinh, m_asinh, 0,
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	823 "asinh(x)\n\nReturn the hyperbolic arc sine (measured in radians) of x.")
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	824 FUNC1(atan, atan, 0,
19048 e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	825 "atan(x)\n\nReturn the arc tangent (measured in radians) of x.")
46516 ec48490b969a Merged revisions 62420-62421,62423-62424 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46505 diff changeset	826 FUNC2(atan2, m_atan2,
19048 e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	827 "atan2(y, x)\n\nReturn the arc tangent (measured in radians) of y/x.\n"
e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	828 "Unlike atan(y/x), the signs of both x and y are considered.")
57866 9751ddcc1882 Merged revisions 76978 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57808 diff changeset	829 FUNC1(atanh, m_atanh, 0,
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	830 "atanh(x)\n\nReturn the hyperbolic arc tangent (measured in radians) of x.")
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	831
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	832 static PyObject * math_ceil(PyObject self, PyObject number) {
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	833 static PyObject *ceil_str = NULL;
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	834 PyObject *method;
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	835
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	836 if (ceil_str == NULL) {
45029 ef2d3bf8383d Merged revisions 60379-60382 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44999 diff changeset	837 ceil_str = PyUnicode_InternFromString("__ceil__");
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	838 if (ceil_str == NULL)
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	839 return NULL;
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	840 }
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	841
44351 86a2679dca46 #1629: Renamed Py_Size, Py_Type and Py_Refcnt to Py_SIZE, Py_TYPE and Py_REFCNT. Christian Heimes <christian@cheimes.de> parents: 42754 diff changeset	842 method = _PyType_Lookup(Py_TYPE(number), ceil_str);
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	843 if (method == NULL)
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	844 return math_1_to_int(number, ceil, 0);
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	845 else
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	846 return PyObject_CallFunction(method, "O", number);
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	847 }
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	848
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	849 PyDoc_STRVAR(math_ceil_doc,
44499 31e294d08ce1 Make math.floor and math.ceil return ints instead of floats. Jeffrey Yasskin <jyasskin@gmail.com> parents: 44460 diff changeset	850 "ceil(x)\n\nReturn the ceiling of x as an int.\n"
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	851 "This is the smallest integral value >= x.");
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	852
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	853 FUNC2(copysign, copysign,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	854 "copysign(x, y)\n\nReturn x with the sign of y.")
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	855 FUNC1(cos, cos, 0,
19048 e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	856 "cos(x)\n\nReturn the cosine of x (measured in radians).")
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	857 FUNC1(cosh, cosh, 1,
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	858 "cosh(x)\n\nReturn the hyperbolic cosine of x.")
57770 1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	859 FUNC1A(erf, m_erf,
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	860 "erf(x)\n\nError function at x.")
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	861 FUNC1A(erfc, m_erfc,
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	862 "erfc(x)\n\nComplementary error function at x.")
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	863 FUNC1(exp, exp, 1,
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	864 "exp(x)\n\nReturn e raised to the power of x.")
57758 b45ca11b9a3e Merged revisions 76861 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57660 diff changeset	865 FUNC1(expm1, m_expm1, 1,
b45ca11b9a3e Merged revisions 76861 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57660 diff changeset	866 "expm1(x)\n\nReturn exp(x)-1.\n"
b45ca11b9a3e Merged revisions 76861 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57660 diff changeset	867 "This function avoids the loss of precision involved in the direct "
b45ca11b9a3e Merged revisions 76861 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57660 diff changeset	868 "evaluation of exp(x)-1 for small x.")
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	869 FUNC1(fabs, fabs, 0,
19048 e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	870 "fabs(x)\n\nReturn the absolute value of the float x.")
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	871
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	872 static PyObject * math_floor(PyObject self, PyObject number) {
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	873 static PyObject *floor_str = NULL;
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	874 PyObject *method;
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	875
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	876 if (floor_str == NULL) {
45029 ef2d3bf8383d Merged revisions 60379-60382 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44999 diff changeset	877 floor_str = PyUnicode_InternFromString("__floor__");
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	878 if (floor_str == NULL)
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	879 return NULL;
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	880 }
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	881
44351 86a2679dca46 #1629: Renamed Py_Size, Py_Type and Py_Refcnt to Py_SIZE, Py_TYPE and Py_REFCNT. Christian Heimes <christian@cheimes.de> parents: 42754 diff changeset	882 method = _PyType_Lookup(Py_TYPE(number), floor_str);
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	883 if (method == NULL)
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	884 return math_1_to_int(number, floor, 0);
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	885 else
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	886 return PyObject_CallFunction(method, "O", number);
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	887 }
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	888
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	889 PyDoc_STRVAR(math_floor_doc,
44499 31e294d08ce1 Make math.floor and math.ceil return ints instead of floats. Jeffrey Yasskin <jyasskin@gmail.com> parents: 44460 diff changeset	890 "floor(x)\n\nReturn the floor of x as an int.\n"
42754 1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	891 "This is the largest integral value <= x.");
1c98b445d847 Fix math.ceil() and math.floor() to fall back to __ceil__ and __floor__ Guido van Rossum <guido@python.org> parents: 42334 diff changeset	892
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	893 FUNC1A(gamma, m_tgamma,
47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	894 "gamma(x)\n\nGamma function at x.")
57660 7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	895 FUNC1A(lgamma, m_lgamma,
7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	896 "lgamma(x)\n\nNatural logarithm of absolute value of Gamma function at x.")
57866 9751ddcc1882 Merged revisions 76978 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57808 diff changeset	897 FUNC1(log1p, m_log1p, 1,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	898 "log1p(x)\n\nReturn the natural logarithm of 1+x (base e).\n"
b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	899 "The result is computed in a way which is accurate for x near zero.")
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	900 FUNC1(sin, sin, 0,
19048 e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	901 "sin(x)\n\nReturn the sine of x (measured in radians).")
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	902 FUNC1(sinh, sinh, 1,
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	903 "sinh(x)\n\nReturn the hyperbolic sine of x.")
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	904 FUNC1(sqrt, sqrt, 0,
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	905 "sqrt(x)\n\nReturn the square root of x.")
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	906 FUNC1(tan, tan, 0,
19048 e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	907 "tan(x)\n\nReturn the tangent of x (measured in radians).")
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	908 FUNC1(tanh, tanh, 0,
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	909 "tanh(x)\n\nReturn the hyperbolic tangent of x.")
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	910
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	911 /* Precision summation function as msum() by Raymond Hettinger in
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	912 <http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/393090>,
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	913 enhanced with the exact partials sum and roundoff from Mark
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	914 Dickinson's post at <http://bugs.python.org/file10357/msum4.py>.
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	915 See those links for more details, proofs and other references.
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	916
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	917 Note 1: IEEE 754R floating point semantics are assumed,
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	918 but the current implementation does not re-establish special
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	919 value semantics across iterations (i.e. handling -Inf + Inf).
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	920
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	921 Note 2: No provision is made for intermediate overflow handling;
47559 2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	922 therefore, sum([1e+308, 1e-308, 1e+308]) returns 1e+308 while
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	923 sum([1e+308, 1e+308, 1e-308]) raises an OverflowError due to the
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	924 overflow of the first partial sum.
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	925
48407 e22deaeb6c1b Merged revisions 64365,64370,64406,64408-64409,64412,64416-64417,64420-64421,64425-64428 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 48331 diff changeset	926 Note 3: The intermediate values lo, yr, and hi are declared volatile so
e22deaeb6c1b Merged revisions 64365,64370,64406,64408-64409,64412,64416-64417,64420-64421,64425-64428 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 48331 diff changeset	927 aggressive compilers won't algebraically reduce lo to always be exactly 0.0.
47559 2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	928 Also, the volatile declaration forces the values to be stored in memory as
2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	929 regular doubles instead of extended long precision (80-bit) values. This
48407 e22deaeb6c1b Merged revisions 64365,64370,64406,64408-64409,64412,64416-64417,64420-64421,64425-64428 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 48331 diff changeset	930 prevents double rounding because any addition or subtraction of two doubles
47559 2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	931 can be resolved exactly into double-sized hi and lo values. As long as the
2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	932 hi value gets forced into a double before yr and lo are computed, the extra
2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	933 bits in downstream extended precision operations (x87 for example) will be
2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	934 exactly zero and therefore can be losslessly stored back into a double,
2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	935 thereby preventing double rounding.
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	936
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	937 Note 4: A similar implementation is in Modules/cmathmodule.c.
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	938 Be sure to update both when making changes.
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	939
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	940 Note 5: The signature of math.fsum() differs from __builtin__.sum()
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	941 because the start argument doesn't make sense in the context of
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	942 accurate summation. Since the partials table is collapsed before
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	943 returning a result, sum(seq2, start=sum(seq1)) may not equal the
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	944 accurate result returned by sum(itertools.chain(seq1, seq2)).
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	945 */
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	946
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	947 #define NUM_PARTIALS 32 /* initial partials array size, on stack */
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	948
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	949 /* Extend the partials array p[] by doubling its size. */
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	950 static int /* non-zero on error */
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	951 _fsum_realloc(double **p_ptr, Py_ssize_t n,
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	952 double ps, Py_ssize_t m_ptr)
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	953 {
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	954 void *v = NULL;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	955 Py_ssize_t m = *m_ptr;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	956
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	957 m += m; /* double */
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	958 if (n < m && m < (PY_SSIZE_T_MAX / sizeof(double))) {
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	959 double p = p_ptr;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	960 if (p == ps) {
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	961 v = PyMem_Malloc(sizeof(double) * m);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	962 if (v != NULL)
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	963 memcpy(v, ps, sizeof(double) * n);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	964 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	965 else
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	966 v = PyMem_Realloc(p, sizeof(double) * m);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	967 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	968 if (v == NULL) { /* size overflow or no memory */
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	969 PyErr_SetString(PyExc_MemoryError, "math.fsum partials");
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	970 return 1;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	971 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	972 p_ptr = (double) v;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	973 *m_ptr = m;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	974 return 0;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	975 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	976
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	977 /* Full precision summation of a sequence of floats.
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	978
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	979 def msum(iterable):
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	980 partials = [] # sorted, non-overlapping partial sums
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	981 for x in iterable:
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	982 i = 0
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	983 for y in partials:
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	984 if abs(x) < abs(y):
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	985 x, y = y, x
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	986 hi = x + y
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	987 lo = y - (hi - x)
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	988 if lo:
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	989 partials[i] = lo
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	990 i += 1
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	991 x = hi
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	992 partials[i:] = [x]
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	993 return sum_exact(partials)
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	994
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	995 Rounded x+y stored in hi with the roundoff stored in lo. Together hi+lo
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	996 are exactly equal to x+y. The inner loop applies hi/lo summation to each
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	997 partial so that the list of partial sums remains exact.
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	998
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	999 Sum_exact() adds the partial sums exactly and correctly rounds the final
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1000 result (using the round-half-to-even rule). The items in partials remain
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1001 non-zero, non-special, non-overlapping and strictly increasing in
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1002 magnitude, but possibly not all having the same sign.
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1003
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1004 Depends on IEEE 754 arithmetic guarantees and half-even rounding.
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1005 */
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1006
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1007 static PyObject*
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1008 math_fsum(PyObject self, PyObject seq)
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1009 {
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1010 PyObject item, iter, *sum = NULL;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1011 Py_ssize_t i, j, n = 0, m = NUM_PARTIALS;
47559 2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	1012 double x, y, t, ps[NUM_PARTIALS], *p = ps;
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1013 double xsave, special_sum = 0.0, inf_sum = 0.0;
47559 2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	1014 volatile double hi, yr, lo;
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1015
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1016 iter = PyObject_GetIter(seq);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1017 if (iter == NULL)
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1018 return NULL;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1019
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1020 PyFPE_START_PROTECT("fsum", Py_DECREF(iter); return NULL)
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1021
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1022 for(;;) { /* for x in iterable */
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1023 assert(0 <= n && n <= m);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1024 assert((m == NUM_PARTIALS && p == ps) \|\|
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1025 (m > NUM_PARTIALS && p != NULL));
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1026
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1027 item = PyIter_Next(iter);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1028 if (item == NULL) {
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1029 if (PyErr_Occurred())
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1030 goto _fsum_error;
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1031 break;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1032 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1033 x = PyFloat_AsDouble(item);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1034 Py_DECREF(item);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1035 if (PyErr_Occurred())
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1036 goto _fsum_error;
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1037
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1038 xsave = x;
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1039 for (i = j = 0; j < n; j++) { /* for y in partials */
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1040 y = p[j];
47559 2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	1041 if (fabs(x) < fabs(y)) {
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1042 t = x; x = y; y = t;
47559 2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	1043 }
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1044 hi = x + y;
47559 2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	1045 yr = hi - x;
2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	1046 lo = y - yr;
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1047 if (lo != 0.0)
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1048 p[i++] = lo;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1049 x = hi;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1050 }
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1051
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1052 n = i; /* ps[i:] = [x] */
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1053 if (x != 0.0) {
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1054 if (! Py_IS_FINITE(x)) {
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1055 /* a nonfinite x could arise either as
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1056 a result of intermediate overflow, or
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1057 as a result of a nan or inf in the
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1058 summands */
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1059 if (Py_IS_FINITE(xsave)) {
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1060 PyErr_SetString(PyExc_OverflowError,
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1061 "intermediate overflow in fsum");
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1062 goto _fsum_error;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1063 }
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1064 if (Py_IS_INFINITY(xsave))
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1065 inf_sum += xsave;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1066 special_sum += xsave;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1067 /* reset partials */
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1068 n = 0;
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1069 }
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1070 else if (n >= m && _fsum_realloc(&p, n, ps, &m))
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1071 goto _fsum_error;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1072 else
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1073 p[n++] = x;
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1074 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1075 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1076
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1077 if (special_sum != 0.0) {
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1078 if (Py_IS_NAN(inf_sum))
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1079 PyErr_SetString(PyExc_ValueError,
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1080 "-inf + inf in fsum");
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1081 else
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1082 sum = PyFloat_FromDouble(special_sum);
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1083 goto _fsum_error;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1084 }
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1085
47559 2925b568aacc Merged revisions 63562,63570,63728,63734,63784,63788,63802,63817,63827,63839,63887,63975,63998 via svnmerge from Georg Brandl <georg@python.org> parents: 47320 diff changeset	1086 hi = 0.0;
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1087 if (n > 0) {
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1088 hi = p[--n];
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1089 /* sum_exact(ps, hi) from the top, stop when the sum becomes
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1090 inexact. */
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1091 while (n > 0) {
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1092 x = hi;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1093 y = p[--n];
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1094 assert(fabs(y) < fabs(x));
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1095 hi = x + y;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1096 yr = hi - x;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1097 lo = y - yr;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1098 if (lo != 0.0)
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1099 break;
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1100 }
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1101 /* Make half-even rounding work across multiple partials.
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1102 Needed so that sum([1e-16, 1, 1e16]) will round-up the last
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1103 digit to two instead of down to zero (the 1e-16 makes the 1
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1104 slightly closer to two). With a potential 1 ULP rounding
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1105 error fixed-up, math.fsum() can guarantee commutativity. */
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1106 if (n > 0 && ((lo < 0.0 && p[n-1] < 0.0) \|\|
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1107 (lo > 0.0 && p[n-1] > 0.0))) {
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1108 y = lo * 2.0;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1109 x = hi + y;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1110 yr = x - hi;
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1111 if (y == yr)
f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1112 hi = x;
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1113 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1114 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1115 sum = PyFloat_FromDouble(hi);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1116
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1117 _fsum_error:
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1118 PyFPE_END_PROTECT(hi)
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1119 Py_DECREF(iter);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1120 if (p != ps)
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1121 PyMem_Free(p);
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1122 return sum;
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1123 }
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1124
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1125 #undef NUM_PARTIALS
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1126
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1127 PyDoc_STRVAR(math_fsum_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1128 "fsum(iterable)\n\n\
47320 3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1129 Return an accurate floating point sum of values in the iterable.\n\
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1130 Assumes IEEE-754 floating point arithmetic.");
3975ec2b0de2 Merged revisions 63542-63544,63546,63553,63563-63564,63567,63569,63576 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47175 diff changeset	1131
4635 49745ddb4f69 Renamed Barry Warsaw <barry@python.org> parents: 4503 diff changeset	1132 static PyObject *
47562 bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1133 math_factorial(PyObject self, PyObject arg)
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1134 {
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1135 long i, x;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1136 PyObject result, iobj, *newresult;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1137
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1138 if (PyFloat_Check(arg)) {
57808 53f21f08af0d Merged revisions 76916 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57770 diff changeset	1139 PyObject *lx;
47562 bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1140 double dx = PyFloat_AS_DOUBLE((PyFloatObject *)arg);
57808 53f21f08af0d Merged revisions 76916 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57770 diff changeset	1141 if (!(Py_IS_FINITE(dx) && dx == floor(dx))) {
47562 bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1142 PyErr_SetString(PyExc_ValueError,
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1143 "factorial() only accepts integral values");
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1144 return NULL;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1145 }
57808 53f21f08af0d Merged revisions 76916 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57770 diff changeset	1146 lx = PyLong_FromDouble(dx);
53f21f08af0d Merged revisions 76916 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57770 diff changeset	1147 if (lx == NULL)
53f21f08af0d Merged revisions 76916 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57770 diff changeset	1148 return NULL;
53f21f08af0d Merged revisions 76916 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57770 diff changeset	1149 x = PyLong_AsLong(lx);
53f21f08af0d Merged revisions 76916 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57770 diff changeset	1150 Py_DECREF(lx);
47562 bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1151 }
57808 53f21f08af0d Merged revisions 76916 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57770 diff changeset	1152 else
53f21f08af0d Merged revisions 76916 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57770 diff changeset	1153 x = PyLong_AsLong(arg);
47562 bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1154
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1155 if (x == -1 && PyErr_Occurred())
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1156 return NULL;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1157 if (x < 0) {
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1158 PyErr_SetString(PyExc_ValueError,
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1159 "factorial() not defined for negative values");
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1160 return NULL;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1161 }
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1162
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1163 result = (PyObject *)PyLong_FromLong(1);
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1164 if (result == NULL)
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1165 return NULL;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1166 for (i=1 ; i<=x ; i++) {
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1167 iobj = (PyObject *)PyLong_FromLong(i);
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1168 if (iobj == NULL)
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1169 goto error;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1170 newresult = PyNumber_Multiply(result, iobj);
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1171 Py_DECREF(iobj);
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1172 if (newresult == NULL)
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1173 goto error;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1174 Py_DECREF(result);
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1175 result = newresult;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1176 }
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1177 return result;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1178
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1179 error:
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1180 Py_DECREF(result);
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1181 return NULL;
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1182 }
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1183
50250 1adfabcbe073 Merged revisions 67886-67887 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 50123 diff changeset	1184 PyDoc_STRVAR(math_factorial_doc,
1adfabcbe073 Merged revisions 67886-67887 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 50123 diff changeset	1185 "factorial(x) -> Integral\n"
1adfabcbe073 Merged revisions 67886-67887 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 50123 diff changeset	1186 "\n"
1adfabcbe073 Merged revisions 67886-67887 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 50123 diff changeset	1187 "Find x!. Raise a ValueError if x is negative or non-integral.");
47562 bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1188
bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1189 static PyObject *
45082 d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1190 math_trunc(PyObject self, PyObject number)
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1191 {
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1192 static PyObject *trunc_str = NULL;
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1193 PyObject *trunc;
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1194
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1195 if (Py_TYPE(number)->tp_dict == NULL) {
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1196 if (PyType_Ready(Py_TYPE(number)) < 0)
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1197 return NULL;
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1198 }
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1199
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1200 if (trunc_str == NULL) {
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1201 trunc_str = PyUnicode_InternFromString("__trunc__");
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1202 if (trunc_str == NULL)
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1203 return NULL;
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1204 }
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1205
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1206 trunc = _PyType_Lookup(Py_TYPE(number), trunc_str);
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1207 if (trunc == NULL) {
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1208 PyErr_Format(PyExc_TypeError,
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1209 "type %.100s doesn't define __trunc__ method",
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1210 Py_TYPE(number)->tp_name);
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1211 return NULL;
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1212 }
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1213 return PyObject_CallFunctionObjArgs(trunc, number, NULL);
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1214 }
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1215
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1216 PyDoc_STRVAR(math_trunc_doc,
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1217 "trunc(x:Real) -> Integral\n"
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1218 "\n"
45134 bdcf40d1b38e Merged revisions 60481,60485,60489-60520,60523-60527,60530-60533,60535-60538,60540-60551 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45082 diff changeset	1219 "Truncates x to the nearest Integral toward 0. Uses the __trunc__ magic method.");
45082 d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1220
d7540031b959 Merged revisions 60475-60479,60481-60488 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45029 diff changeset	1221 static PyObject *
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1222 math_frexp(PyObject self, PyObject arg)
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1223 {
9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1224 int i;
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1225 double x = PyFloat_AsDouble(arg);
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1226 if (x == -1.0 && PyErr_Occurred())
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1227 return NULL;
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1228 /* deal with special cases directly, to sidestep platform
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1229 differences */
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1230 if (Py_IS_NAN(x) \|\| Py_IS_INFINITY(x) \|\| !x) {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1231 i = 0;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1232 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1233 else {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1234 PyFPE_START_PROTECT("in math_frexp", return 0);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1235 x = frexp(x, &i);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1236 PyFPE_END_PROTECT(x);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1237 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1238 return Py_BuildValue("(di)", x, i);
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1239 }
9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1240
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1241 PyDoc_STRVAR(math_frexp_doc,
19712 b4521436e8f8 Mechanical fiddling to make this easier to work with in my editor. Tim Peters <tim.peters@gmail.com> parents: 19048 diff changeset	1242 "frexp(x)\n"
b4521436e8f8 Mechanical fiddling to make this easier to work with in my editor. Tim Peters <tim.peters@gmail.com> parents: 19048 diff changeset	1243 "\n"
b4521436e8f8 Mechanical fiddling to make this easier to work with in my editor. Tim Peters <tim.peters@gmail.com> parents: 19048 diff changeset	1244 "Return the mantissa and exponent of x, as pair (m, e).\n"
b4521436e8f8 Mechanical fiddling to make this easier to work with in my editor. Tim Peters <tim.peters@gmail.com> parents: 19048 diff changeset	1245 "m is a float and e is an int, such that x = m * 2.**e.\n"
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1246 "If x is 0, m and e are both 0. Else 0.5 <= abs(m) < 1.0.");
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	1247
4635 49745ddb4f69 Renamed Barry Warsaw <barry@python.org> parents: 4503 diff changeset	1248 static PyObject *
13326 24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	1249 math_ldexp(PyObject self, PyObject args)
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1250 {
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1251 double x, r;
47063 081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1252 PyObject *oexp;
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1253 long exp;
58125 9b9adc42c73a Merged revisions 77275 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 58088 diff changeset	1254 int overflow;
47063 081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1255 if (! PyArg_ParseTuple(args, "dO:ldexp", &x, &oexp))
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1256 return NULL;
47063 081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1257
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1258 if (PyLong_Check(oexp)) {
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1259 /* on overflow, replace exponent with either LONG_MAX
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1260 or LONG_MIN, depending on the sign. */
58125 9b9adc42c73a Merged revisions 77275 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 58088 diff changeset	1261 exp = PyLong_AsLongAndOverflow(oexp, &overflow);
9b9adc42c73a Merged revisions 77275 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 58088 diff changeset	1262 if (exp == -1 && PyErr_Occurred())
9b9adc42c73a Merged revisions 77275 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 58088 diff changeset	1263 return NULL;
9b9adc42c73a Merged revisions 77275 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 58088 diff changeset	1264 if (overflow)
9b9adc42c73a Merged revisions 77275 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 58088 diff changeset	1265 exp = overflow < 0 ? LONG_MIN : LONG_MAX;
47063 081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1266 }
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1267 else {
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1268 PyErr_SetString(PyExc_TypeError,
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1269 "Expected an int or long as second argument "
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1270 "to ldexp.");
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1271 return NULL;
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1272 }
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1273
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1274 if (x == 0. \|\| !Py_IS_FINITE(x)) {
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1275 /* NaNs, zeros and infinities are returned unchanged */
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1276 r = x;
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1277 errno = 0;
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1278 } else if (exp > INT_MAX) {
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1279 /* overflow */
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1280 r = copysign(Py_HUGE_VAL, x);
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1281 errno = ERANGE;
47063 081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1282 } else if (exp < INT_MIN) {
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1283 /* underflow to +-0 */
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1284 r = copysign(0., x);
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1285 errno = 0;
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1286 } else {
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1287 errno = 0;
47063 081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1288 PyFPE_START_PROTECT("in math_ldexp", return 0);
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1289 r = ldexp(x, (int)exp);
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1290 PyFPE_END_PROTECT(r);
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1291 if (Py_IS_INFINITY(r))
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1292 errno = ERANGE;
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1293 }
081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1294
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1295 if (errno && is_error(r))
15170 09c7ac188ce2 Stop raising OverflowError on underflows reported by libm (errno==ERANGE and Tim Peters <tim.peters@gmail.com> parents: 14616 diff changeset	1296 return NULL;
47063 081c15806e28 Merged revisions 62914-62916,62918-62919,62921-62922,62924-62942,62944-62945,62947-62949 via svnmerge from Alexandre Vassalotti <alexandre@peadrop.com> parents: 46791 diff changeset	1297 return PyFloat_FromDouble(r);
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1298 }
9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1299
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1300 PyDoc_STRVAR(math_ldexp_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1301 "ldexp(x, i)\n\n\
b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1302 Return x * (2**i).");
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	1303
4635 49745ddb4f69 Renamed Barry Warsaw <barry@python.org> parents: 4503 diff changeset	1304 static PyObject *
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1305 math_modf(PyObject self, PyObject arg)
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1306 {
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1307 double y, x = PyFloat_AsDouble(arg);
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1308 if (x == -1.0 && PyErr_Occurred())
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1309 return NULL;
46505 63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1310 /* some platforms don't do the right thing for NaNs and
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1311 infinities, so we take care of special cases directly. */
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1312 if (!Py_IS_FINITE(x)) {
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1313 if (Py_IS_INFINITY(x))
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1314 return Py_BuildValue("(dd)", copysign(0., x), x);
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1315 else if (Py_IS_NAN(x))
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1316 return Py_BuildValue("(dd)", x, x);
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1317 }
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1318
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1319 errno = 0;
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1320 PyFPE_START_PROTECT("in math_modf", return 0);
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1321 x = modf(x, &y);
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1322 PyFPE_END_PROTECT(x);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1323 return Py_BuildValue("(dd)", x, y);
407 9b3d557665a9 Added frexp, ldexp, modf, fmod. Guido van Rossum <guido@python.org> parents: 320 diff changeset	1324 }
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	1325
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1326 PyDoc_STRVAR(math_modf_doc,
19712 b4521436e8f8 Mechanical fiddling to make this easier to work with in my editor. Tim Peters <tim.peters@gmail.com> parents: 19048 diff changeset	1327 "modf(x)\n"
b4521436e8f8 Mechanical fiddling to make this easier to work with in my editor. Tim Peters <tim.peters@gmail.com> parents: 19048 diff changeset	1328 "\n"
b4521436e8f8 Mechanical fiddling to make this easier to work with in my editor. Tim Peters <tim.peters@gmail.com> parents: 19048 diff changeset	1329 "Return the fractional and integer parts of x. Both results carry the sign\n"
50250 1adfabcbe073 Merged revisions 67886-67887 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 50123 diff changeset	1330 "of x and are floats.");
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	1331
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1332 /* A decent logarithm is easy to compute even for huge longs, but libm can't
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1333 do that by itself -- loghelper can. func is log or log10, and name is
58088 46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1334 "log" or "log10". Note that overflow of the result isn't possible: a long
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1335 can contain no more than INT_MAX * SHIFT bits, so has value certainly less
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1336 than 2(264 * 216) == 2280, and log2 of that is 280, which is
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1337 small enough to fit in an IEEE single. log and log10 are even smaller.
58088 46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1338 However, intermediate overflow is possible for a long if the number of bits
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1339 in that long is larger than PY_SSIZE_T_MAX. */
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1340
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1341 static PyObject*
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1342 loghelper(PyObject* arg, double (func)(double), char funcname)
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1343 {
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1344 /* If it is long, do it ourselves. */
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1345 if (PyLong_Check(arg)) {
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1346 double x;
58088 46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1347 Py_ssize_t e;
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1348 x = _PyLong_Frexp((PyLongObject *)arg, &e);
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1349 if (x == -1.0 && PyErr_Occurred())
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1350 return NULL;
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1351 if (x <= 0.0) {
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1352 PyErr_SetString(PyExc_ValueError,
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1353 "math domain error");
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1354 return NULL;
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1355 }
58088 46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1356 /* Special case for log(1), to make sure we get an
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1357 exact result there. */
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1358 if (e == 1 && x == 0.5)
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1359 return PyFloat_FromDouble(0.0);
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1360 /* Value is ~= x * 2*e, so the log ~= log(x) + log(2) e. */
46d60e5ff103 Merged revisions 77234 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57866 diff changeset	1361 x = func(x) + func(2.0) * e;
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1362 return PyFloat_FromDouble(x);
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1363 }
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1364
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1365 /* Else let libm handle it by itself. */
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1366 return math_1(arg, func, 0);
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1367 }
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1368
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1369 static PyObject *
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1370 math_log(PyObject self, PyObject args)
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1371 {
26661 b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1372 PyObject *arg;
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1373 PyObject *base = NULL;
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1374 PyObject num, den;
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1375 PyObject *ans;
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1376
26818 e094a03a80ff SF patch #659536: Use PyArg_UnpackTuple where possible. Raymond Hettinger <python@rcn.com> parents: 26661 diff changeset	1377 if (!PyArg_UnpackTuple(args, "log", 1, 2, &arg, &base))
26661 b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1378 return NULL;
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1379
50123 20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	1380 num = loghelper(arg, m_log, "log");
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1381 if (num == NULL \|\| base == NULL)
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1382 return num;
26661 b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1383
50123 20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	1384 den = loghelper(base, m_log, "log");
26661 b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1385 if (den == NULL) {
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1386 Py_DECREF(num);
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1387 return NULL;
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1388 }
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1389
37191 4bfe8afe8f65 Get rid of remnants of integer division Neal Norwitz <nnorwitz@gmail.com> parents: 36324 diff changeset	1390 ans = PyNumber_TrueDivide(num, den);
26661 b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1391 Py_DECREF(num);
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1392 Py_DECREF(den);
b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1393 return ans;
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1394 }
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1395
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1396 PyDoc_STRVAR(math_log_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1397 "log(x[, base])\n\n\
b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1398 Return the logarithm of x to the given base.\n\
26661 b12e326b4ea2 Apply SF patch 652930: Add optional base argument to math.log(x[, base]). Raymond Hettinger <python@rcn.com> parents: 24471 diff changeset	1399 If the base not specified, returns the natural logarithm (base e) of x.");
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1400
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1401 static PyObject *
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1402 math_log10(PyObject self, PyObject arg)
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1403 {
50123 20a84e063052 Merged revisions 67708 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48606 diff changeset	1404 return loghelper(arg, m_log10, "log10");
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1405 }
9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1406
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1407 PyDoc_STRVAR(math_log10_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1408 "log10(x)\n\nReturn the base 10 logarithm of x.");
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1409
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1410 static PyObject *
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1411 math_fmod(PyObject self, PyObject args)
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1412 {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1413 PyObject ox, oy;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1414 double r, x, y;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1415 if (! PyArg_UnpackTuple(args, "fmod", 2, 2, &ox, &oy))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1416 return NULL;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1417 x = PyFloat_AsDouble(ox);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1418 y = PyFloat_AsDouble(oy);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1419 if ((x == -1.0 \|\| y == -1.0) && PyErr_Occurred())
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1420 return NULL;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1421 /* fmod(x, +/-Inf) returns x for finite x. */
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1422 if (Py_IS_INFINITY(y) && Py_IS_FINITE(x))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1423 return PyFloat_FromDouble(x);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1424 errno = 0;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1425 PyFPE_START_PROTECT("in math_fmod", return 0);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1426 r = fmod(x, y);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1427 PyFPE_END_PROTECT(r);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1428 if (Py_IS_NAN(r)) {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1429 if (!Py_IS_NAN(x) && !Py_IS_NAN(y))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1430 errno = EDOM;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1431 else
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1432 errno = 0;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1433 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1434 if (errno && is_error(r))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1435 return NULL;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1436 else
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1437 return PyFloat_FromDouble(r);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1438 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1439
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1440 PyDoc_STRVAR(math_fmod_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1441 "fmod(x, y)\n\nReturn fmod(x, y), according to platform C."
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1442 " x % y may differ.");
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1443
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1444 static PyObject *
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1445 math_hypot(PyObject self, PyObject args)
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1446 {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1447 PyObject ox, oy;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1448 double r, x, y;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1449 if (! PyArg_UnpackTuple(args, "hypot", 2, 2, &ox, &oy))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1450 return NULL;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1451 x = PyFloat_AsDouble(ox);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1452 y = PyFloat_AsDouble(oy);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1453 if ((x == -1.0 \|\| y == -1.0) && PyErr_Occurred())
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1454 return NULL;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1455 /* hypot(x, +/-Inf) returns Inf, even if x is a NaN. */
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1456 if (Py_IS_INFINITY(x))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1457 return PyFloat_FromDouble(fabs(x));
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1458 if (Py_IS_INFINITY(y))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1459 return PyFloat_FromDouble(fabs(y));
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1460 errno = 0;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1461 PyFPE_START_PROTECT("in math_hypot", return 0);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1462 r = hypot(x, y);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1463 PyFPE_END_PROTECT(r);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1464 if (Py_IS_NAN(r)) {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1465 if (!Py_IS_NAN(x) && !Py_IS_NAN(y))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1466 errno = EDOM;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1467 else
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1468 errno = 0;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1469 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1470 else if (Py_IS_INFINITY(r)) {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1471 if (Py_IS_FINITE(x) && Py_IS_FINITE(y))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1472 errno = ERANGE;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1473 else
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1474 errno = 0;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1475 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1476 if (errno && is_error(r))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1477 return NULL;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1478 else
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1479 return PyFloat_FromDouble(r);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1480 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1481
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1482 PyDoc_STRVAR(math_hypot_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1483 "hypot(x, y)\n\nReturn the Euclidean distance, sqrt(xx + yy).");
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1484
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1485 /* pow can't use math_2, but needs its own wrapper: the problem is
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1486 that an infinite result can arise either as a result of overflow
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1487 (in which case OverflowError should be raised) or as a result of
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1488 e.g. 0.**-5. (for which ValueError needs to be raised.)
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1489 */
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1490
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1491 static PyObject *
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1492 math_pow(PyObject self, PyObject args)
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1493 {
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1494 PyObject ox, oy;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1495 double r, x, y;
46505 63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1496 int odd_y;
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1497
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1498 if (! PyArg_UnpackTuple(args, "pow", 2, 2, &ox, &oy))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1499 return NULL;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1500 x = PyFloat_AsDouble(ox);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1501 y = PyFloat_AsDouble(oy);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1502 if ((x == -1.0 \|\| y == -1.0) && PyErr_Occurred())
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1503 return NULL;
46505 63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1504
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1505 /* deal directly with IEEE specials, to cope with problems on various
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1506 platforms whose semantics don't exactly match C99 */
46664 031dfe455585 Merged revisions 62425-62429,62434-62436,62441,62444,62446-62448,62450-62455,62463,62465-62466,62469,62474,62476-62478,62480,62485,62492,62497-62498,62500,62507,62513-62514,62516,62521,62531,62535,62545-62546,62548-62551,62553-62559,62569,62574,62577,62593,62595,62604-62606,62608,62616,62626-62627,62636,62638,62644-62645,62647-62648,62651-62653,62656,62661,62663,62680,62686-62687,62696,62699-62703,62711 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46621 diff changeset	1507 r = 0.; /* silence compiler warning */
46505 63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1508 if (!Py_IS_FINITE(x) \|\| !Py_IS_FINITE(y)) {
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1509 errno = 0;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1510 if (Py_IS_NAN(x))
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1511 r = y == 0. ? 1. : x; /* NaN*0 = 1 /
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1512 else if (Py_IS_NAN(y))
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1513 r = x == 1. ? 1. : y; /* 1*NaN = 1 /
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1514 else if (Py_IS_INFINITY(x)) {
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1515 odd_y = Py_IS_FINITE(y) && fmod(fabs(y), 2.0) == 1.0;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1516 if (y > 0.)
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1517 r = odd_y ? x : fabs(x);
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1518 else if (y == 0.)
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1519 r = 1.;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1520 else /* y < 0. */
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1521 r = odd_y ? copysign(0., x) : 0.;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1522 }
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1523 else if (Py_IS_INFINITY(y)) {
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1524 if (fabs(x) == 1.0)
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1525 r = 1.;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1526 else if (y > 0. && fabs(x) > 1.0)
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1527 r = y;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1528 else if (y < 0. && fabs(x) < 1.0) {
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1529 r = -y; /* result is +inf */
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1530 if (x == 0.) /* 0*-inf: divide-by-zero /
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1531 errno = EDOM;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1532 }
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1533 else
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1534 r = 0.;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1535 }
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1536 }
46505 63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1537 else {
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1538 /* let libm handle finite*finite /
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1539 errno = 0;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1540 PyFPE_START_PROTECT("in math_pow", return 0);
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1541 r = pow(x, y);
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1542 PyFPE_END_PROTECT(r);
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1543 /* a NaN result should arise only from (-ve)**(finite
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1544 non-integer); in this case we want to raise ValueError. */
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1545 if (!Py_IS_FINITE(r)) {
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1546 if (Py_IS_NAN(r)) {
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1547 errno = EDOM;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1548 }
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1549 /*
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1550 an infinite result here arises either from:
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1551 (A) (+/-0.)**negative (-> divide-by-zero)
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1552 (B) overflow of x**y with x and y finite
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1553 */
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1554 else if (Py_IS_INFINITY(r)) {
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1555 if (x == 0.)
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1556 errno = EDOM;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1557 else
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1558 errno = ERANGE;
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1559 }
63965327b3ef Merged revisions 62386-62387,62389-62393,62396,62400-62402,62407,62409-62410,62412-62414,62418-62419 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 46477 diff changeset	1560 }
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1561 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1562
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1563 if (errno && is_error(r))
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1564 return NULL;
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1565 else
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1566 return PyFloat_FromDouble(r);
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1567 }
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1568
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1569 PyDoc_STRVAR(math_pow_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1570 "pow(x, y)\n\nReturn x**y (x to the power of y).");
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1571
44441 b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1572 static const double degToRad = Py_MATH_PI / 180.0;
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1573 static const double radToDeg = 180.0 / Py_MATH_PI;
23427 a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1574
a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1575 static PyObject *
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1576 math_degrees(PyObject self, PyObject arg)
23427 a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1577 {
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1578 double x = PyFloat_AsDouble(arg);
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1579 if (x == -1.0 && PyErr_Occurred())
23427 a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1580 return NULL;
44441 b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1581 return PyFloat_FromDouble(x * radToDeg);
23427 a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1582 }
a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1583
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1584 PyDoc_STRVAR(math_degrees_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1585 "degrees(x)\n\n\
b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1586 Convert angle x from radians to degrees.");
23427 a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1587
a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1588 static PyObject *
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1589 math_radians(PyObject self, PyObject arg)
23427 a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1590 {
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1591 double x = PyFloat_AsDouble(arg);
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1592 if (x == -1.0 && PyErr_Occurred())
23427 a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1593 return NULL;
a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1594 return PyFloat_FromDouble(x * degToRad);
a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1595 }
a4d675b8b53c Added degrees() and radians() to mathmodule. Closes patch 552452 and Raymond Hettinger <python@rcn.com> parents: 19758 diff changeset	1596
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1597 PyDoc_STRVAR(math_radians_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1598 "radians(x)\n\n\
b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1599 Convert angle x from degrees to radians.");
19713 9433dd3c197e Return reasonable results for math.log(long) and math.log10(long) (we were Tim Peters <tim.peters@gmail.com> parents: 19712 diff changeset	1600
44441 b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1601 static PyObject *
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1602 math_isnan(PyObject self, PyObject arg)
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1603 {
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1604 double x = PyFloat_AsDouble(arg);
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1605 if (x == -1.0 && PyErr_Occurred())
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1606 return NULL;
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1607 return PyBool_FromLong((long)Py_IS_NAN(x));
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1608 }
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1609
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1610 PyDoc_STRVAR(math_isnan_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1611 "isnan(x) -> bool\n\n\
b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1612 Check if float x is not a number (NaN).");
44441 b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1613
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1614 static PyObject *
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1615 math_isinf(PyObject self, PyObject arg)
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1616 {
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1617 double x = PyFloat_AsDouble(arg);
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1618 if (x == -1.0 && PyErr_Occurred())
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1619 return NULL;
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1620 return PyBool_FromLong((long)Py_IS_INFINITY(x));
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1621 }
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1622
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1623 PyDoc_STRVAR(math_isinf_doc,
57209 b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1624 "isinf(x) -> bool\n\n\
b354c1b6b476 Merged revisions 75149,75260-75263,75265-75267,75292,75300,75376,75405,75429-75433,75437,75445,75501,75551,75572,75589-75591,75657,75742,75868,75952-75957,76057,76105,76139,76143,76162,76223 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 56270 diff changeset	1625 Check if float x is infinite (positive or negative).");
44441 b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1626
4635 49745ddb4f69 Renamed Barry Warsaw <barry@python.org> parents: 4503 diff changeset	1627 static PyMethodDef math_methods[] = {
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1628 {"acos", math_acos, METH_O, math_acos_doc},
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1629 {"acosh", math_acosh, METH_O, math_acosh_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1630 {"asin", math_asin, METH_O, math_asin_doc},
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1631 {"asinh", math_asinh, METH_O, math_asinh_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1632 {"atan", math_atan, METH_O, math_atan_doc},
13326 24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	1633 {"atan2", math_atan2, METH_VARARGS, math_atan2_doc},
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1634 {"atanh", math_atanh, METH_O, math_atanh_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1635 {"ceil", math_ceil, METH_O, math_ceil_doc},
44441 b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1636 {"copysign", math_copysign, METH_VARARGS, math_copysign_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1637 {"cos", math_cos, METH_O, math_cos_doc},
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1638 {"cosh", math_cosh, METH_O, math_cosh_doc},
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1639 {"degrees", math_degrees, METH_O, math_degrees_doc},
57770 1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	1640 {"erf", math_erf, METH_O, math_erf_doc},
1e8164b5f36d Merged revisions 76878 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57758 diff changeset	1641 {"erfc", math_erfc, METH_O, math_erfc_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1642 {"exp", math_exp, METH_O, math_exp_doc},
57758 b45ca11b9a3e Merged revisions 76861 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57660 diff changeset	1643 {"expm1", math_expm1, METH_O, math_expm1_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1644 {"fabs", math_fabs, METH_O, math_fabs_doc},
47562 bd584f121c4b Merged revisions 64002-64003,64012,64036-64037,64047,64050-64052,64054-64055,64066,64071 via svnmerge from Georg Brandl <georg@python.org> parents: 47559 diff changeset	1645 {"factorial", math_factorial, METH_O, math_factorial_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1646 {"floor", math_floor, METH_O, math_floor_doc},
13326 24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	1647 {"fmod", math_fmod, METH_VARARGS, math_fmod_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1648 {"frexp", math_frexp, METH_O, math_frexp_doc},
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1649 {"fsum", math_fsum, METH_O, math_fsum_doc},
56270 47b82fbdc2bb Merged revisions 75117 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 50250 diff changeset	1650 {"gamma", math_gamma, METH_O, math_gamma_doc},
13326 24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	1651 {"hypot", math_hypot, METH_VARARGS, math_hypot_doc},
44441 b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1652 {"isinf", math_isinf, METH_O, math_isinf_doc},
b91ca87e6f32 Merged revisions 59666-59679 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44351 diff changeset	1653 {"isnan", math_isnan, METH_O, math_isnan_doc},
13326 24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	1654 {"ldexp", math_ldexp, METH_VARARGS, math_ldexp_doc},
57660 7cb73e7c176d Merged revisions 76755 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 57209 diff changeset	1655 {"lgamma", math_lgamma, METH_O, math_lgamma_doc},
13326 24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	1656 {"log", math_log, METH_VARARGS, math_log_doc},
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1657 {"log1p", math_log1p, METH_O, math_log1p_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1658 {"log10", math_log10, METH_O, math_log10_doc},
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1659 {"modf", math_modf, METH_O, math_modf_doc},
13326 24717405dd89 ANSI-fication, remove Py_PROTO, etc. Fred Drake <fdrake@acm.org> parents: 13309 diff changeset	1660 {"pow", math_pow, METH_VARARGS, math_pow_doc},
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1661 {"radians", math_radians, METH_O, math_radians_doc},
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1662 {"sin", math_sin, METH_O, math_sin_doc},
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1663 {"sinh", math_sinh, METH_O, math_sinh_doc},
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1664 {"sqrt", math_sqrt, METH_O, math_sqrt_doc},
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1665 {"tan", math_tan, METH_O, math_tan_doc},
cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 37191 diff changeset	1666 {"tanh", math_tanh, METH_O, math_tanh_doc},
48606 f121a963ab69 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48407 diff changeset	1667 {"trunc", math_trunc, METH_O, math_trunc_doc},
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	1668 {NULL, NULL} /* sentinel */
fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	1669 };
fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	1670
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	1671
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1672 PyDoc_STRVAR(module_doc,
19712 b4521436e8f8 Mechanical fiddling to make this easier to work with in my editor. Tim Peters <tim.peters@gmail.com> parents: 19048 diff changeset	1673 "This module is always available. It provides access to the\n"
23832 ed1ba37a46b7 Patch #568124: Add doc string macros. Martin v. Löwis <martin@v.loewis.de> parents: 23427 diff changeset	1674 "mathematical functions defined by the C standard.");
9593 f22f769bf3d9 Added Doc strings -- by Chris Petrilli. Guido van Rossum <guido@python.org> parents: 9588 diff changeset	1675
47580 94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1676
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1677 static struct PyModuleDef mathmodule = {
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1678 PyModuleDef_HEAD_INIT,
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1679 "math",
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1680 module_doc,
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1681 -1,
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1682 math_methods,
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1683 NULL,
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1684 NULL,
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1685 NULL,
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1686 NULL
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1687 };
94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1688
24471 f66b3a3509c7 Excise DL_EXPORT/DL_IMPORT from Modules/. Required adding a prototype Mark Hammond <mhammond@skippinet.com.au>* parents: 23832 diff changeset	1689 PyMODINIT_FUNC
47580 94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1690 PyInit_math(void)
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	1691 {
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1692 PyObject *m;
19048 e282d6b2b758 Part of SF patch [#431848] mathmodule.c: doc strings & conversion, from Tim Peters <tim.peters@gmail.com> parents: 18066 diff changeset	1693
47580 94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1694 m = PyModule_Create(&mathmodule);
36324 1af7f719ed28 Check return result from Py_InitModule(). This API can fail. Neal Norwitz <nnorwitz@gmail.com>* parents: 34872 diff changeset	1695 if (m == NULL)
1af7f719ed28 Check return result from Py_InitModule(). This API can fail. Neal Norwitz <nnorwitz@gmail.com>* parents: 34872 diff changeset	1696 goto finally;
4752 7367fb107108 Better error checking in initmath(). Barry Warsaw <barry@python.org> parents: 4635 diff changeset	1697
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1698 PyModule_AddObject(m, "pi", PyFloat_FromDouble(Py_MATH_PI));
b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1699 PyModule_AddObject(m, "e", PyFloat_FromDouble(Py_MATH_E));
4752 7367fb107108 Better error checking in initmath(). Barry Warsaw <barry@python.org> parents: 4635 diff changeset	1700
46477 b69f443ef480 Merged revisions 62380,62382-62383 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 45134 diff changeset	1701 finally:
47580 94f64f11fdd0 Implement PEP 3121: new module initialization and finalization API. Martin v. Löwis <martin@v.loewis.de> parents: 47562 diff changeset	1702 return m;
6 fc6fcd7df4f7 Initial revision Guido van Rossum <guido@python.org> parents: diff changeset	1703 }

Mercurial > cpython-lru_cache-weakref

annotate Modules/mathmodule.c @ 60008:0dfd62076ded