diff options
Diffstat (limited to 'missing/erf.c')
| -rw-r--r-- | missing/erf.c | 29 |
1 files changed, 5 insertions, 24 deletions
diff --git a/missing/erf.c b/missing/erf.c index dad2644a7e..c2c9d5f7e9 100644 --- a/missing/erf.c +++ b/missing/erf.c @@ -3,31 +3,15 @@ reference - Haruhiko Okumura: C-gengo niyoru saishin algorithm jiten (New Algorithm handbook in C language) (Gijyutsu hyouron sha, Tokyo, 1991) p.227 [in Japanese] */ -#include "missing.h" +#include "ruby/missing.h" #include <stdio.h> #include <math.h> -#ifdef _WIN32 -# include <float.h> -# if !defined __MINGW32__ || defined __NO_ISOCEXT -# ifndef isnan -# define isnan(x) _isnan(x) -# endif -# ifndef isinf -# define isinf(x) (!_finite(x) && !_isnan(x)) -# endif -# ifndef finite -# define finite(x) _finite(x) -# endif -# endif -#endif - static double q_gamma(double, double, double); /* Incomplete gamma function 1 / Gamma(a) * Int_0^x exp(-t) t^(a-1) dt */ -static double p_gamma(a, x, loggamma_a) - double a, x, loggamma_a; +static double p_gamma(double a, double x, double loggamma_a) { int k; double result, term, previous; @@ -46,8 +30,7 @@ static double p_gamma(a, x, loggamma_a) /* Incomplete gamma function 1 / Gamma(a) * Int_x^inf exp(-t) t^(a-1) dt */ -static double q_gamma(a, x, loggamma_a) - double a, x, loggamma_a; +static double q_gamma(double a, double x, double loggamma_a) { int k; double result, w, temp, previous; @@ -70,8 +53,7 @@ static double q_gamma(a, x, loggamma_a) #define LOG_PI_OVER_2 0.572364942924700087071713675675 /* log_e(PI)/2 */ -double erf(x) - double x; +double erf(double x) { if (!finite(x)) { if (isnan(x)) return x; /* erf(NaN) = NaN */ @@ -81,8 +63,7 @@ double erf(x) else return - p_gamma(0.5, x * x, LOG_PI_OVER_2); } -double erfc(x) - double x; +double erfc(double x) { if (!finite(x)) { if (isnan(x)) return x; /* erfc(NaN) = NaN */ |