* mingwex/math/lgamma.c: New file.

* mingwex/math/lgammaf.c: New file.
	* mingwex/math/lgammal.c: New file.
	* mingwex/math/tgamma.c: New file.
	* mingwex/math/tgammaf.c: New file.
	* mingwex/math/tgammal.c: New file.
	* mingwex/math/cephes_mconf (polevlf): Add float version.
	(p1evlf): Likewise.
	Define _CEPHES_USE_ERRNO.
	* mingwex/Makefile.in (MATH_DISTFILES): Add new files.
	(MATH_OBJS): Add new objects.
	* include/math.h (lgamma[fl]): Add prototypes.
	(tgamma[fl]): Add prototypes.
This commit is contained in:
Danny Smith 2002-11-27 03:41:25 +00:00
parent eb6d2e2f9a
commit dc8597f966
9 changed files with 2300 additions and 5 deletions

View File

@ -501,7 +501,21 @@ extern long double powl (long double, long double);
extern float sqrtf (float); extern float sqrtf (float);
extern long double sqrtl (long double); extern long double sqrtl (long double);
/* 7.12.8 Error and gamma functions: TODO */ /* TODO */
/* 7.12.8.1 The erf functions */
/* 7.12.8.2 The erfc functions */
/* 7.12.8.3 The lgamma functions */
extern double lgamma (double);
extern float lgammaf (float);
extern long double lgammal (long double);
/* 77.12.8.4 The tgamma functions */
extern double tgamma (double);
extern float tgammaf (float);
extern long double tgammal (long double);
/* 7.12.9.1 Double in C89 */ /* 7.12.9.1 Double in C89 */
extern float ceilf (float); extern float ceilf (float);

View File

@ -46,7 +46,8 @@ MATH_DISTFILES = \
fmodl.c fp_consts.c fp_consts.h fp_constsf.c fp_constsl.c \ fmodl.c fp_consts.c fp_consts.h fp_constsf.c fp_constsl.c \
fpclassify.c fpclassifyf.c fpclassifyl.c \ fpclassify.c fpclassifyf.c fpclassifyl.c \
frexpf.c frexpl.S fucom.c hypotf.c hypotl.c ilogb.S ilogbf.S \ frexpf.c frexpl.S fucom.c hypotf.c hypotl.c ilogb.S ilogbf.S \
ilogbl.S isnan.c isnanf.c isnanl.c ldexpf.c ldexpl.c llrint.c \ ilogbl.S isnan.c isnanf.c isnanl.c ldexpf.c ldexpl.c \
lgamma.c lgammaf.c lgammal.c llrint.c \
llrintf.c llrintl.c llround.c llroundf.c llroundl.c \ llrintf.c llrintl.c llround.c llroundf.c llroundl.c \
log10f.S log10l.S log1p.S log1pf.S log1pl.S log2.S log2f.S \ log10f.S log10l.S log1p.S log1pf.S log1pl.S log2.S log2f.S \
log2l.S logb.c logbf.c logbl.c logf.S logl.S lrint.c lrintf.c \ log2l.S logb.c logbf.c logbl.c logf.S logl.S lrint.c lrintf.c \
@ -57,7 +58,8 @@ MATH_DISTFILES = \
remquof.S remquol.S rint.c rintf.c rintl.c round.c roundf.c \ remquof.S remquol.S rint.c rintf.c rintl.c round.c roundf.c \
roundl.c scalbn.S scalbnf.S scalbnl.S signbit.c signbitf.c \ roundl.c scalbn.S scalbnf.S scalbnl.S signbit.c signbitf.c \
signbitl.c sinf.S sinhf.c sinhl.c sinl.S sqrtf.c sqrtl.c \ signbitl.c sinf.S sinhf.c sinhl.c sinl.S sqrtf.c sqrtl.c \
tanf.S tanhf.c tanhl.c tanl.S trunc.c truncf.c truncl.c tanf.S tanhf.c tanhl.c tanl.S tgamma.c tgammaf.c tgammal.c \
trunc.c truncf.c truncl.c
CC = @CC@ CC = @CC@
# FIXME: Which is it, CC or CC_FOR_TARGET? # FIXME: Which is it, CC or CC_FOR_TARGET?
@ -115,7 +117,8 @@ MATH_OBJS = \
fmodl.o fp_consts.o fp_constsf.o fp_constsl.o \ fmodl.o fp_consts.o fp_constsf.o fp_constsl.o \
fpclassify.o fpclassifyf.o fpclassifyl.o \ fpclassify.o fpclassifyf.o fpclassifyl.o \
frexpf.o frexpl.o fucom.o hypotf.o hypotl.o ilogb.o ilogbf.o \ frexpf.o frexpl.o fucom.o hypotf.o hypotl.o ilogb.o ilogbf.o \
ilogbl.o isnan.o isnanf.o isnanl.o ldexpf.o ldexpl.o llrint.o \ ilogbl.o isnan.o isnanf.o isnanl.o ldexpf.o ldexpl.o \
lgamma.o lgammaf.o lgammal.o llrint.o \
llrintf.o llrintl.o llround.o llroundf.o llroundl.o \ llrintf.o llrintl.o llround.o llroundf.o llroundl.o \
log10f.o log10l.o log1p.o log1pf.o log1pl.o log2.o log2f.o \ log10f.o log10l.o log1p.o log1pf.o log1pl.o log2.o log2f.o \
log2l.o logb.o logbf.o logbl.o logf.o logl.o lrint.o lrintf.o \ log2l.o logb.o logbf.o logbl.o logf.o logl.o lrint.o lrintf.o \
@ -126,7 +129,8 @@ MATH_OBJS = \
remquof.o remquol.o rint.o rintf.o rintl.o round.o roundf.o \ remquof.o remquol.o rint.o rintf.o rintl.o round.o roundf.o \
roundl.o scalbn.o scalbnf.o scalbnl.o signbit.o signbitf.o \ roundl.o scalbn.o scalbnf.o scalbnl.o signbit.o signbitf.o \
signbitl.o sinf.o sinhf.o sinhl.o sinl.o sqrtf.o sqrtl.o \ signbitl.o sinf.o sinhf.o sinhl.o sinl.o sqrtf.o sqrtl.o \
tanf.o tanhf.o tanhl.o tanl.o trunc.o truncf.o truncl.o tanf.o tanhf.o tanhl.o tanl.o tgamma.o tgammaf.o tgammal.o \
trunc.o truncf.o truncl.o
FENV_OBJS = fesetround.o fegetround.o \ FENV_OBJS = fesetround.o fegetround.o \
fegetenv.o fesetenv.o feupdateenv.o \ fegetenv.o fesetenv.o feupdateenv.o \
feclearexcept.o feholdexcept.o fegetexceptflag.o \ feclearexcept.o feholdexcept.o fegetexceptflag.o \

View File

@ -12,6 +12,8 @@
#define mtherr(fname, code) #define mtherr(fname, code)
#define XPD 0, #define XPD 0,
#define _CEPHES_USE_ERRNO
#ifdef _CEPHES_USE_ERRNO #ifdef _CEPHES_USE_ERRNO
#define _SET_ERRNO(x) errno = (x) #define _SET_ERRNO(x) errno = (x)
#else #else
@ -275,3 +277,99 @@ while( --n );
return( y ); return( y );
} }
/* Float version */
/* polevlf.c
* p1evlf.c
*
* Evaluate polynomial
*
*
*
* SYNOPSIS:
*
* int N;
* float x, y, coef[N+1], polevlf[];
*
* y = polevlf( x, coef, N );
*
*
*
* DESCRIPTION:
*
* Evaluates polynomial of degree N:
*
* 2 N
* y = C + C x + C x +...+ C x
* 0 1 2 N
*
* Coefficients are stored in reverse order:
*
* coef[0] = C , ..., coef[N] = C .
* N 0
*
* The function p1evl() assumes that coef[N] = 1.0 and is
* omitted from the array. Its calling arguments are
* otherwise the same as polevl().
*
*
* SPEED:
*
* In the interest of speed, there are no checks for out
* of bounds arithmetic. This routine is used by most of
* the functions in the library. Depending on available
* equipment features, the user may wish to rewrite the
* program in microcode or assembly language.
*
*/
/*
Cephes Math Library Release 2.1: December, 1988
Copyright 1984, 1987, 1988 by Stephen L. Moshier
Direct inquiries to 30 Frost Street, Cambridge, MA 02140
*/
static __inline__ float polevlf(float x, const float* coef, int N )
{
float ans;
float *p;
int i;
p = (float*)coef;
ans = *p++;
/*
for( i=0; i<N; i++ )
ans = ans * x + *p++;
*/
i = N;
do
ans = ans * x + *p++;
while( --i );
return( ans );
}
/* p1evl() */
/* N
* Evaluate polynomial when coefficient of x is 1.0.
* Otherwise same as polevl.
*/
static __inline__ float p1evlf( float x, const float *coef, int N )
{
float ans;
float *p;
int i;
p = (float*)coef;
ans = x + *p++;
i = N-1;
do
ans = ans * x + *p++;
while( --i );
return( ans );
}

View File

@ -0,0 +1,359 @@
/* lgam()
*
* Natural logarithm of gamma function
*
*
*
* SYNOPSIS:
*
* double x, y, __lgamma_r();
* int* sgngam;
* y = __lgamma_r( x, sgngam );
*
* double x, y, lgamma();
* y = lgamma( x);
*
*
*
* DESCRIPTION:
*
* Returns the base e (2.718...) logarithm of the absolute
* value of the gamma function of the argument. In the reentrant
* version, the sign (+1 or -1) of the gamma function is returned
* in the variable referenced by sgngam.
*
* For arguments greater than 13, the logarithm of the gamma
* function is approximated by the logarithmic version of
* Stirling's formula using a polynomial approximation of
* degree 4. Arguments between -33 and +33 are reduced by
* recurrence to the interval [2,3] of a rational approximation.
* The cosecant reflection formula is employed for arguments
* less than -33.
*
* Arguments greater than MAXLGM return MAXNUM and an error
* message. MAXLGM = 2.035093e36 for DEC
* arithmetic or 2.556348e305 for IEEE arithmetic.
*
*
*
* ACCURACY:
*
*
* arithmetic domain # trials peak rms
* DEC 0, 3 7000 5.2e-17 1.3e-17
* DEC 2.718, 2.035e36 5000 3.9e-17 9.9e-18
* IEEE 0, 3 28000 5.4e-16 1.1e-16
* IEEE 2.718, 2.556e305 40000 3.5e-16 8.3e-17
* The error criterion was relative when the function magnitude
* was greater than one but absolute when it was less than one.
*
* The following test used the relative error criterion, though
* at certain points the relative error could be much higher than
* indicated.
* IEEE -200, -4 10000 4.8e-16 1.3e-16
*
*/
/*
* Cephes Math Library Release 2.8: June, 2000
* Copyright 1984, 1987, 1989, 1992, 2000 by Stephen L. Moshier
*/
/*
* 26-11-2002 Modified for mingw.
* Danny Smith <dannysmith@users.sourceforge.net>
*/
#ifndef __MINGW32__
#include "mconf.h"
#ifdef ANSIPROT
extern double pow ( double, double );
extern double log ( double );
extern double exp ( double );
extern double sin ( double );
extern double polevl ( double, void *, int );
extern double p1evl ( double, void *, int );
extern double floor ( double );
extern double fabs ( double );
extern int isnan ( double );
extern int isfinite ( double );
#else
double pow(), log(), exp(), sin(), polevl(), p1evl(), floor(), fabs();
int isnan(), isfinite();
#endif
#ifdef INFINITIES
extern double INFINITY;
#endif
#ifdef NANS
extern double NAN;
#endif
#else /* __MINGW32__ */
#include "cephes_mconf.h"
#endif /* __MINGW32__ */
/* A[]: Stirling's formula expansion of log gamma
* B[], C[]: log gamma function between 2 and 3
*/
#ifdef UNK
static double A[] = {
8.11614167470508450300E-4,
-5.95061904284301438324E-4,
7.93650340457716943945E-4,
-2.77777777730099687205E-3,
8.33333333333331927722E-2
};
static double B[] = {
-1.37825152569120859100E3,
-3.88016315134637840924E4,
-3.31612992738871184744E5,
-1.16237097492762307383E6,
-1.72173700820839662146E6,
-8.53555664245765465627E5
};
static double C[] = {
/* 1.00000000000000000000E0, */
-3.51815701436523470549E2,
-1.70642106651881159223E4,
-2.20528590553854454839E5,
-1.13933444367982507207E6,
-2.53252307177582951285E6,
-2.01889141433532773231E6
};
/* log( sqrt( 2*pi ) ) */
static double LS2PI = 0.91893853320467274178;
#define MAXLGM 2.556348e305
static double LOGPI = 1.14472988584940017414;
#endif
#ifdef DEC
static const unsigned short A[] = {
0035524,0141201,0034633,0031405,
0135433,0176755,0126007,0045030,
0035520,0006371,0003342,0172730,
0136066,0005540,0132605,0026407,
0037252,0125252,0125252,0125132
};
static const unsigned short B[] = {
0142654,0044014,0077633,0035410,
0144027,0110641,0125335,0144760,
0144641,0165637,0142204,0047447,
0145215,0162027,0146246,0155211,
0145322,0026110,0010317,0110130,
0145120,0061472,0120300,0025363
};
static const unsigned short C[] = {
/*0040200,0000000,0000000,0000000*/
0142257,0164150,0163630,0112622,
0143605,0050153,0156116,0135272,
0144527,0056045,0145642,0062332,
0145213,0012063,0106250,0001025,
0145432,0111254,0044577,0115142,
0145366,0071133,0050217,0005122
};
/* log( sqrt( 2*pi ) ) */
static const unsigned short LS2P[] = {040153,037616,041445,0172645,};
#define LS2PI *(double *)LS2P
#define MAXLGM 2.035093e36
static const unsigned short LPI[4] = {
0040222,0103202,0043475,0006750,
};
#define LOGPI *(double *)LPI
#endif
#ifdef IBMPC
static const unsigned short A[] = {
0x6661,0x2733,0x9850,0x3f4a,
0xe943,0xb580,0x7fbd,0xbf43,
0x5ebb,0x20dc,0x019f,0x3f4a,
0xa5a1,0x16b0,0xc16c,0xbf66,
0x554b,0x5555,0x5555,0x3fb5
};
static const unsigned short B[] = {
0x6761,0x8ff3,0x8901,0xc095,
0xb93e,0x355b,0xf234,0xc0e2,
0x89e5,0xf890,0x3d73,0xc114,
0xdb51,0xf994,0xbc82,0xc131,
0xf20b,0x0219,0x4589,0xc13a,
0x055e,0x5418,0x0c67,0xc12a
};
static const unsigned short C[] = {
/*0x0000,0x0000,0x0000,0x3ff0,*/
0x12b2,0x1cf3,0xfd0d,0xc075,
0xd757,0x7b89,0xaa0d,0xc0d0,
0x4c9b,0xb974,0xeb84,0xc10a,
0x0043,0x7195,0x6286,0xc131,
0xf34c,0x892f,0x5255,0xc143,
0xe14a,0x6a11,0xce4b,0xc13e
};
/* log( sqrt( 2*pi ) ) */
static const unsigned short LS2P[] = {
0xbeb5,0xc864,0x67f1,0x3fed
};
#define LS2PI *(double *)LS2P
#define MAXLGM 2.556348e305
static const unsigned short LPI[4] = {
0xa1bd,0x48e7,0x50d0,0x3ff2,
};
#define LOGPI *(double *)LPI
#endif
#ifdef MIEEE
static const unsigned short A[] = {
0x3f4a,0x9850,0x2733,0x6661,
0xbf43,0x7fbd,0xb580,0xe943,
0x3f4a,0x019f,0x20dc,0x5ebb,
0xbf66,0xc16c,0x16b0,0xa5a1,
0x3fb5,0x5555,0x5555,0x554b
};
static const unsigned short B[] = {
0xc095,0x8901,0x8ff3,0x6761,
0xc0e2,0xf234,0x355b,0xb93e,
0xc114,0x3d73,0xf890,0x89e5,
0xc131,0xbc82,0xf994,0xdb51,
0xc13a,0x4589,0x0219,0xf20b,
0xc12a,0x0c67,0x5418,0x055e
};
static const unsigned short C[] = {
0xc075,0xfd0d,0x1cf3,0x12b2,
0xc0d0,0xaa0d,0x7b89,0xd757,
0xc10a,0xeb84,0xb974,0x4c9b,
0xc131,0x6286,0x7195,0x0043,
0xc143,0x5255,0x892f,0xf34c,
0xc13e,0xce4b,0x6a11,0xe14a
};
/* log( sqrt( 2*pi ) ) */
static const unsigned short LS2P[] = {
0x3fed,0x67f1,0xc864,0xbeb5
};
#define LS2PI *(double *)LS2P
#define MAXLGM 2.556348e305
static unsigned short LPI[4] = {
0x3ff2,0x50d0,0x48e7,0xa1bd,
};
#define LOGPI *(double *)LPI
#endif
/* Logarithm of gamma function */
/* Reentrant version */
double __lgamma_r(double x, int* sgngam)
{
double p, q, u, w, z;
int i;
*sgngam = 1;
#ifdef NANS
if( isnan(x) )
return(x);
#endif
#ifdef INFINITIES
if( !isfinite(x) )
return(INFINITY);
#endif
if( x < -34.0 )
{
q = -x;
w = __lgamma_r(q, sgngam); /* note this modifies sgngam! */
p = floor(q);
if( p == q )
{
lgsing:
_SET_ERRNO(EDOM);
mtherr( "lgam", SING );
#ifdef INFINITIES
return (INFINITY);
#else
return (MAXNUM);
#endif
}
i = p;
if( (i & 1) == 0 )
*sgngam = -1;
else
*sgngam = 1;
z = q - p;
if( z > 0.5 )
{
p += 1.0;
z = p - q;
}
z = q * sin( PI * z );
if( z == 0.0 )
goto lgsing;
/* z = log(PI) - log( z ) - w;*/
z = LOGPI - log( z ) - w;
return( z );
}
if( x < 13.0 )
{
z = 1.0;
p = 0.0;
u = x;
while( u >= 3.0 )
{
p -= 1.0;
u = x + p;
z *= u;
}
while( u < 2.0 )
{
if( u == 0.0 )
goto lgsing;
z /= u;
p += 1.0;
u = x + p;
}
if( z < 0.0 )
{
*sgngam = -1;
z = -z;
}
else
*sgngam = 1;
if( u == 2.0 )
return( log(z) );
p -= 2.0;
x = x + p;
p = x * polevl( x, B, 5 ) / p1evl( x, C, 6);
return( log(z) + p );
}
if( x > MAXLGM )
{
_SET_ERRNO(ERANGE);
mtherr( "lgamma", OVERFLOW );
#ifdef INFINITIES
return( *sgngam * INFINITY );
#else
return( *sgngam * MAXNUM );
#endif
}
q = ( x - 0.5 ) * log(x) - x + LS2PI;
if( x > 1.0e8 )
return( q );
p = 1.0/(x*x);
if( x >= 1000.0 )
q += (( 7.9365079365079365079365e-4 * p
- 2.7777777777777777777778e-3) *p
+ 0.0833333333333333333333) / x;
else
q += polevl( p, A, 4 ) / x;
return( q );
}
/* This is the C99 version */
double lgamma(double x)
{
int local_sgngam=0;
return (__lgamma_r(x, &local_sgngam));
}

View File

@ -0,0 +1,253 @@
/* lgamf()
*
* Natural logarithm of gamma function
*
*
*
* SYNOPSIS:
*
* float x, y, __lgammaf_r();
* int* sgngamf;
* y = __lgammaf_r( x, sgngamf );
*
* float x, y, lgammaf();
* y = lgammaf( x);
*
*
*
* DESCRIPTION:
*
* Returns the base e (2.718...) logarithm of the absolute
* value of the gamma function of the argument. In the reentrant
* version the sign (+1 or -1) of the gamma function is returned in
* variable referenced by sgngamf.
*
* For arguments greater than 6.5, the logarithm of the gamma
* function is approximated by the logarithmic version of
* Stirling's formula. Arguments between 0 and +6.5 are reduced by
* by recurrence to the interval [.75,1.25] or [1.5,2.5] of a rational
* approximation. The cosecant reflection formula is employed for
* arguments less than zero.
*
* Arguments greater than MAXLGM = 2.035093e36 return MAXNUM and an
* error message.
*
*
*
* ACCURACY:
*
*
*
* arithmetic domain # trials peak rms
* IEEE -100,+100 500,000 7.4e-7 6.8e-8
* The error criterion was relative when the function magnitude
* was greater than one but absolute when it was less than one.
* The routine has low relative error for positive arguments.
*
* The following test used the relative error criterion.
* IEEE -2, +3 100000 4.0e-7 5.6e-8
*
*/
/*
Cephes Math Library Release 2.7: July, 1998
Copyright 1984, 1987, 1989, 1992, 1998 by Stephen L. Moshier
*/
/*
26-11-2002 Modified for mingw.
Danny Smith <dannysmith@users.sourceforge.net>
*/
/* log gamma(x+2), -.5 < x < .5 */
static const float B[] = {
6.055172732649237E-004,
-1.311620815545743E-003,
2.863437556468661E-003,
-7.366775108654962E-003,
2.058355474821512E-002,
-6.735323259371034E-002,
3.224669577325661E-001,
4.227843421859038E-001
};
/* log gamma(x+1), -.25 < x < .25 */
static const float C[] = {
1.369488127325832E-001,
-1.590086327657347E-001,
1.692415923504637E-001,
-2.067882815621965E-001,
2.705806208275915E-001,
-4.006931650563372E-001,
8.224670749082976E-001,
-5.772156501719101E-001
};
/* log( sqrt( 2*pi ) ) */
static const float LS2PI = 0.91893853320467274178;
#define MAXLGM 2.035093e36
static const float PIINV = 0.318309886183790671538;
#ifndef __MINGW32__
#include "mconf.h"
float floorf(float);
float polevlf( float, float *, int );
float p1evlf( float, float *, int );
#else
#include "cephes_mconf.h"
#endif
/* Reentrant version */
/* Logarithm of gamma function */
float __lgammaf_r( float x, int* sgngamf )
{
float p, q, w, z;
float nx, tx;
int i, direction;
*sgngamf = 1;
#ifdef NANS
if( isnan(x) )
return(x);
#endif
#ifdef INFINITIES
if( !isfinite(x) )
return(x);
#endif
if( x < 0.0 )
{
q = -x;
w = __lgammaf_r(q, sgngamf); /* note this modifies sgngam! */
p = floorf(q);
if( p == q )
{
lgsing:
_SET_ERRNO(EDOM);
mtherr( "lgamf", SING );
#ifdef INFINITIES
return (INFINITYF);
#else
return( *sgngamf * MAXNUMF );
#endif
}
i = p;
if( (i & 1) == 0 )
*sgngamf = -1;
else
*sgngamf = 1;
z = q - p;
if( z > 0.5 )
{
p += 1.0;
z = p - q;
}
z = q * sinf( PIF * z );
if( z == 0.0 )
goto lgsing;
z = -logf( PIINV*z ) - w;
return( z );
}
if( x < 6.5 )
{
direction = 0;
z = 1.0;
tx = x;
nx = 0.0;
if( x >= 1.5 )
{
while( tx > 2.5 )
{
nx -= 1.0;
tx = x + nx;
z *=tx;
}
x += nx - 2.0;
iv1r5:
p = x * polevlf( x, B, 7 );
goto cont;
}
if( x >= 1.25 )
{
z *= x;
x -= 1.0; /* x + 1 - 2 */
direction = 1;
goto iv1r5;
}
if( x >= 0.75 )
{
x -= 1.0;
p = x * polevlf( x, C, 7 );
q = 0.0;
goto contz;
}
while( tx < 1.5 )
{
if( tx == 0.0 )
goto lgsing;
z *=tx;
nx += 1.0;
tx = x + nx;
}
direction = 1;
x += nx - 2.0;
p = x * polevlf( x, B, 7 );
cont:
if( z < 0.0 )
{
*sgngamf = -1;
z = -z;
}
else
{
*sgngamf = 1;
}
q = logf(z);
if( direction )
q = -q;
contz:
return( p + q );
}
if( x > MAXLGM )
{
_SET_ERRNO(ERANGE);
mtherr( "lgamf", OVERFLOW );
#ifdef INFINITIES
return( *sgngamf * INFINITYF );
#else
return( *sgngamf * MAXNUMF );
#endif
}
/* Note, though an asymptotic formula could be used for x >= 3,
* there is cancellation error in the following if x < 6.5. */
q = LS2PI - x;
q += ( x - 0.5 ) * logf(x);
if( x <= 1.0e4 )
{
z = 1.0/x;
p = z * z;
q += (( 6.789774945028216E-004 * p
- 2.769887652139868E-003 ) * p
+ 8.333316229807355E-002 ) * z;
}
return( q );
}
/* This is the C99 version */
float lgammaf(float x)
{
int local_sgngamf=0;
return (__lgammaf_r(x, &local_sgngamf));
}

View File

@ -0,0 +1,416 @@
/* lgaml()
*
* Natural logarithm of gamma function
*
*
*
* SYNOPSIS:
*
* long double x, y, __lgammal_r();
* int* sgngaml;
* y = __lgammal_r( x, sgngaml );
*
* long double x, y, lgammal();
* y = lgammal( x);
*
*
*
* DESCRIPTION:
*
* Returns the base e (2.718...) logarithm of the absolute
* value of the gamma function of the argument. In the reentrant
* version, the sign (+1 or -1) of the gamma function is returned
* in the variable referenced by sgngaml.
*
* For arguments greater than 33, the logarithm of the gamma
* function is approximated by the logarithmic version of
* Stirling's formula using a polynomial approximation of
* degree 4. Arguments between -33 and +33 are reduced by
* recurrence to the interval [2,3] of a rational approximation.
* The cosecant reflection formula is employed for arguments
* less than -33.
*
* Arguments greater than MAXLGML (10^4928) return MAXNUML.
*
*
*
* ACCURACY:
*
*
* arithmetic domain # trials peak rms
* IEEE -40, 40 100000 2.2e-19 4.6e-20
* IEEE 10^-2000,10^+2000 20000 1.6e-19 3.3e-20
* The error criterion was relative when the function magnitude
* was greater than one but absolute when it was less than one.
*
*/
/*
* Copyright 1994 by Stephen L. Moshier
*/
/*
* 26-11-2002 Modified for mingw.
* Danny Smith <dannysmith@users.sourceforge.net>
*/
#ifndef __MINGW32__
#include "mconf.h"
#ifdef ANSIPROT
extern long double fabsl ( long double );
extern long double lgaml ( long double );
extern long double logl ( long double );
extern long double expl ( long double );
extern long double gammal ( long double );
extern long double sinl ( long double );
extern long double floorl ( long double );
extern long double powl ( long double, long double );
extern long double polevll ( long double, void *, int );
extern long double p1evll ( long double, void *, int );
extern int isnanl ( long double );
extern int isfinitel ( long double );
#else
long double fabsl(), lgaml(), logl(), expl(), gammal(), sinl();
long double floorl(), powl(), polevll(), p1evll(), isnanl(), isfinitel();
#endif
#ifdef INFINITIES
extern long double INFINITYL;
#endif
#ifdef NANS
extern long double NANL;
#endif
#else /* __MINGW32__ */
#include "cephes_mconf.h"
#endif /* __MINGW32__ */
#if UNK
static long double S[9] = {
-1.193945051381510095614E-3L,
7.220599478036909672331E-3L,
-9.622023360406271645744E-3L,
-4.219773360705915470089E-2L,
1.665386113720805206758E-1L,
-4.200263503403344054473E-2L,
-6.558780715202540684668E-1L,
5.772156649015328608253E-1L,
1.000000000000000000000E0L,
};
#endif
#if IBMPC
static const unsigned short S[] = {
0xbaeb,0xd6d3,0x25e5,0x9c7e,0xbff5, XPD
0xfe9a,0xceb4,0xc74e,0xec9a,0x3ff7, XPD
0x9225,0xdfef,0xb0e9,0x9da5,0xbff8, XPD
0x10b0,0xec17,0x87dc,0xacd7,0xbffa, XPD
0x6b8d,0x7515,0x1905,0xaa89,0x3ffc, XPD
0xf183,0x126b,0xf47d,0xac0a,0xbffa, XPD
0x7bf6,0x57d1,0xa013,0xa7e7,0xbffe, XPD
0xc7a9,0x7db0,0x67e3,0x93c4,0x3ffe, XPD
0x0000,0x0000,0x0000,0x8000,0x3fff, XPD
};
#endif
#if MIEEE
static long S[27] = {
0xbff50000,0x9c7e25e5,0xd6d3baeb,
0x3ff70000,0xec9ac74e,0xceb4fe9a,
0xbff80000,0x9da5b0e9,0xdfef9225,
0xbffa0000,0xacd787dc,0xec1710b0,
0x3ffc0000,0xaa891905,0x75156b8d,
0xbffa0000,0xac0af47d,0x126bf183,
0xbffe0000,0xa7e7a013,0x57d17bf6,
0x3ffe0000,0x93c467e3,0x7db0c7a9,
0x3fff0000,0x80000000,0x00000000,
};
#endif
#if UNK
static long double SN[9] = {
1.133374167243894382010E-3L,
7.220837261893170325704E-3L,
9.621911155035976733706E-3L,
-4.219773343731191721664E-2L,
-1.665386113944413519335E-1L,
-4.200263503402112910504E-2L,
6.558780715202536547116E-1L,
5.772156649015328608727E-1L,
-1.000000000000000000000E0L,
};
#endif
#if IBMPC
static const unsigned SN[] = {
0x5dd1,0x02de,0xb9f7,0x948d,0x3ff5, XPD
0x989b,0xdd68,0xc5f1,0xec9c,0x3ff7, XPD
0x2ca1,0x18f0,0x386f,0x9da5,0x3ff8, XPD
0x783f,0x41dd,0x87d1,0xacd7,0xbffa, XPD
0x7a5b,0xd76d,0x1905,0xaa89,0xbffc, XPD
0x7f64,0x1234,0xf47d,0xac0a,0xbffa, XPD
0x5e26,0x57d1,0xa013,0xa7e7,0x3ffe, XPD
0xc7aa,0x7db0,0x67e3,0x93c4,0x3ffe, XPD
0x0000,0x0000,0x0000,0x8000,0xbfff, XPD
};
#endif
#if MIEEE
static long SN[27] = {
0x3ff50000,0x948db9f7,0x02de5dd1,
0x3ff70000,0xec9cc5f1,0xdd68989b,
0x3ff80000,0x9da5386f,0x18f02ca1,
0xbffa0000,0xacd787d1,0x41dd783f,
0xbffc0000,0xaa891905,0xd76d7a5b,
0xbffa0000,0xac0af47d,0x12347f64,
0x3ffe0000,0xa7e7a013,0x57d15e26,
0x3ffe0000,0x93c467e3,0x7db0c7aa,
0xbfff0000,0x80000000,0x00000000,
};
#endif
/* A[]: Stirling's formula expansion of log gamma
* B[], C[]: log gamma function between 2 and 3
*/
/* log gamma(x) = ( x - 0.5 ) * log(x) - x + LS2PI + 1/x A(1/x^2)
* x >= 8
* Peak relative error 1.51e-21
* Relative spread of error peaks 5.67e-21
*/
#if UNK
static long double A[7] = {
4.885026142432270781165E-3L,
-1.880801938119376907179E-3L,
8.412723297322498080632E-4L,
-5.952345851765688514613E-4L,
7.936507795855070755671E-4L,
-2.777777777750349603440E-3L,
8.333333333333331447505E-2L,
};
#endif
#if IBMPC
static const unsigned short A[] = {
0xd984,0xcc08,0x91c2,0xa012,0x3ff7, XPD
0x3d91,0x0304,0x3da1,0xf685,0xbff5, XPD
0x3bdc,0xaad1,0xd492,0xdc88,0x3ff4, XPD
0x8b20,0x9fce,0x844e,0x9c09,0xbff4, XPD
0xf8f2,0x30e5,0x0092,0xd00d,0x3ff4, XPD
0x4d88,0x03a8,0x60b6,0xb60b,0xbff6, XPD
0x9fcc,0xaaaa,0xaaaa,0xaaaa,0x3ffb, XPD
};
#endif
#if MIEEE
static long A[21] = {
0x3ff70000,0xa01291c2,0xcc08d984,
0xbff50000,0xf6853da1,0x03043d91,
0x3ff40000,0xdc88d492,0xaad13bdc,
0xbff40000,0x9c09844e,0x9fce8b20,
0x3ff40000,0xd00d0092,0x30e5f8f2,
0xbff60000,0xb60b60b6,0x03a84d88,
0x3ffb0000,0xaaaaaaaa,0xaaaa9fcc,
};
#endif
/* log gamma(x+2) = x B(x)/C(x)
* 0 <= x <= 1
* Peak relative error 7.16e-22
* Relative spread of error peaks 4.78e-20
*/
#if UNK
static long double B[7] = {
-2.163690827643812857640E3L,
-8.723871522843511459790E4L,
-1.104326814691464261197E6L,
-6.111225012005214299996E6L,
-1.625568062543700591014E7L,
-2.003937418103815175475E7L,
-8.875666783650703802159E6L,
};
static long double C[7] = {
/* 1.000000000000000000000E0L,*/
-5.139481484435370143617E2L,
-3.403570840534304670537E4L,
-6.227441164066219501697E5L,
-4.814940379411882186630E6L,
-1.785433287045078156959E7L,
-3.138646407656182662088E7L,
-2.099336717757895876142E7L,
};
#endif
#if IBMPC
static const unsigned short B[] = {
0x9557,0x4995,0x0da1,0x873b,0xc00a, XPD
0xfe44,0x9af8,0x5b8c,0xaa63,0xc00f, XPD
0x5aa8,0x7cf5,0x3684,0x86ce,0xc013, XPD
0x259a,0x258c,0xf206,0xba7f,0xc015, XPD
0xbe18,0x1ca3,0xc0a0,0xf80a,0xc016, XPD
0x168f,0x2c42,0x6717,0x98e3,0xc017, XPD
0x2051,0x9d55,0x92c8,0x876e,0xc016, XPD
};
static const unsigned short C[] = {
/*0x0000,0x0000,0x0000,0x8000,0x3fff, XPD*/
0xaa77,0xcf2f,0xae76,0x807c,0xc008, XPD
0xb280,0x0d74,0xb55a,0x84f3,0xc00e, XPD
0xa505,0xcd30,0x81dc,0x9809,0xc012, XPD
0x3369,0x4246,0xb8c2,0x92f0,0xc015, XPD
0x63cf,0x6aee,0xbe6f,0x8837,0xc017, XPD
0x26bb,0xccc7,0xb009,0xef75,0xc017, XPD
0x462b,0xbae8,0xab96,0xa02a,0xc017, XPD
};
#endif
#if MIEEE
static long B[21] = {
0xc00a0000,0x873b0da1,0x49959557,
0xc00f0000,0xaa635b8c,0x9af8fe44,
0xc0130000,0x86ce3684,0x7cf55aa8,
0xc0150000,0xba7ff206,0x258c259a,
0xc0160000,0xf80ac0a0,0x1ca3be18,
0xc0170000,0x98e36717,0x2c42168f,
0xc0160000,0x876e92c8,0x9d552051,
};
static long C[21] = {
/*0x3fff0000,0x80000000,0x00000000,*/
0xc0080000,0x807cae76,0xcf2faa77,
0xc00e0000,0x84f3b55a,0x0d74b280,
0xc0120000,0x980981dc,0xcd30a505,
0xc0150000,0x92f0b8c2,0x42463369,
0xc0170000,0x8837be6f,0x6aee63cf,
0xc0170000,0xef75b009,0xccc726bb,
0xc0170000,0xa02aab96,0xbae8462b,
};
#endif
/* log( sqrt( 2*pi ) ) */
static const long double LS2PI = 0.91893853320467274178L;
#define MAXLGM 1.04848146839019521116e+4928L
/* Logarithm of gamma function */
/* Reentrant version */
long double __lgammal_r(long double x, int* sgngaml)
{
long double p, q, w, z, f, nx;
int i;
*sgngaml = 1;
#ifdef NANS
if( isnanl(x) )
return(NANL);
#endif
#ifdef INFINITIES
if( !isfinitel(x) )
return(INFINITYL);
#endif
if( x < -34.0L )
{
q = -x;
w = __lgammal_r(q, sgngaml); /* note this modifies sgngam! */
p = floorl(q);
if( p == q )
{
lgsing:
_SET_ERRNO(EDOM);
mtherr( "lgammal", SING );
#ifdef INFINITIES
return (INFINITYL);
#else
return (MAXNUML);
#endif
}
i = p;
if( (i & 1) == 0 )
*sgngaml = -1;
else
*sgngaml = 1;
z = q - p;
if( z > 0.5L )
{
p += 1.0L;
z = p - q;
}
z = q * sinl( PIL * z );
if( z == 0.0L )
goto lgsing;
/* z = LOGPI - logl( z ) - w; */
z = logl( PIL/z ) - w;
return( z );
}
if( x < 13.0L )
{
z = 1.0L;
nx = floorl( x + 0.5L );
f = x - nx;
while( x >= 3.0L )
{
nx -= 1.0L;
x = nx + f;
z *= x;
}
while( x < 2.0L )
{
if( fabsl(x) <= 0.03125 )
goto lsmall;
z /= nx + f;
nx += 1.0L;
x = nx + f;
}
if( z < 0.0L )
{
*sgngaml = -1;
z = -z;
}
else
*sgngaml = 1;
if( x == 2.0L )
return( logl(z) );
x = (nx - 2.0L) + f;
p = x * polevll( x, B, 6 ) / p1evll( x, C, 7);
return( logl(z) + p );
}
if( x > MAXLGM )
{
_SET_ERRNO(ERANGE);
mtherr( "lgammal", OVERFLOW );
#ifdef INFINITIES
return( *sgngaml * INFINITYL );
#else
return( *sgngaml * MAXNUML );
#endif
}
q = ( x - 0.5L ) * logl(x) - x + LS2PI;
if( x > 1.0e10L )
return(q);
p = 1.0L/(x*x);
q += polevll( p, A, 6 ) / x;
return( q );
lsmall:
if( x == 0.0L )
goto lgsing;
if( x < 0.0L )
{
x = -x;
q = z / (x * polevll( x, SN, 8 ));
}
else
q = z / (x * polevll( x, S, 8 ));
if( q < 0.0L )
{
*sgngaml = -1;
q = -q;
}
else
*sgngaml = 1;
q = logl( q );
return(q);
}
/* This is the C99 version */
long double lgammal(long double x)
{
int local_sgngaml=0;
return (__lgammal_r(x, &local_sgngaml));
}

View File

@ -0,0 +1,385 @@
/* gamma.c
*
* Gamma function
*
*
*
* SYNOPSIS:
*
* double x, y, __tgamma_r();
* int* sgngam;
* y = __tgamma_r( x, sgngam );
*
* double x, y, tgamma();
* y = tgamma( x)
*
*
*
* DESCRIPTION:
*
* Returns gamma function of the argument. The result is
* correctly signed. In the reentrant version the sign (+1 or -1)
* is returned in the variable referenced by sgngam.
*
* Arguments |x| <= 34 are reduced by recurrence and the function
* approximated by a rational function of degree 6/7 in the
* interval (2,3). Large arguments are handled by Stirling's
* formula. Large negative arguments are made positive using
* a reflection formula.
*
*
* ACCURACY:
*
* Relative error:
* arithmetic domain # trials peak rms
* DEC -34, 34 10000 1.3e-16 2.5e-17
* IEEE -170,-33 20000 2.3e-15 3.3e-16
* IEEE -33, 33 20000 9.4e-16 2.2e-16
* IEEE 33, 171.6 20000 2.3e-15 3.2e-16
*
* Error for arguments outside the test range will be larger
* owing to error amplification by the exponential function.
*
*/
/*
Cephes Math Library Release 2.8: June, 2000
Copyright 1984, 1987, 1989, 1992, 2000 by Stephen L. Moshier
*/
/*
* 26-11-2002 Modified for mingw.
* Danny Smith <dannysmith@users.sourceforge.net>
*/
#ifndef __MINGW32__
#include "mconf.h"
#else
#include "cephes_mconf.h"
#endif
#ifdef UNK
static const double P[] = {
1.60119522476751861407E-4,
1.19135147006586384913E-3,
1.04213797561761569935E-2,
4.76367800457137231464E-2,
2.07448227648435975150E-1,
4.94214826801497100753E-1,
9.99999999999999996796E-1
};
static const double Q[] = {
-2.31581873324120129819E-5,
5.39605580493303397842E-4,
-4.45641913851797240494E-3,
1.18139785222060435552E-2,
3.58236398605498653373E-2,
-2.34591795718243348568E-1,
7.14304917030273074085E-2,
1.00000000000000000320E0
};
#define MAXGAM 171.624376956302725
static const double LOGPI = 1.14472988584940017414;
#endif
#ifdef DEC
static const unsigned short P[] = {
0035047,0162701,0146301,0005234,
0035634,0023437,0032065,0176530,
0036452,0137157,0047330,0122574,
0037103,0017310,0143041,0017232,
0037524,0066516,0162563,0164605,
0037775,0004671,0146237,0014222,
0040200,0000000,0000000,0000000
};
static const unsigned short Q[] = {
0134302,0041724,0020006,0116565,
0035415,0072121,0044251,0025634,
0136222,0003447,0035205,0121114,
0036501,0107552,0154335,0104271,
0037022,0135717,0014776,0171471,
0137560,0034324,0165024,0037021,
0037222,0045046,0047151,0161213,
0040200,0000000,0000000,0000000
};
#define MAXGAM 34.84425627277176174
#endif
#ifdef IBMPC
static const unsigned short P[] = {
0x2153,0x3998,0xfcb8,0x3f24,
0xbfab,0xe686,0x84e3,0x3f53,
0x14b0,0xe9db,0x57cd,0x3f85,
0x23d3,0x18c4,0x63d9,0x3fa8,
0x7d31,0xdcae,0x8da9,0x3fca,
0xe312,0x3993,0xa137,0x3fdf,
0x0000,0x0000,0x0000,0x3ff0
};
static const unsigned short Q[] = {
0xd3af,0x8400,0x487a,0xbef8,
0x2573,0x2915,0xae8a,0x3f41,
0xb44a,0xe750,0x40e4,0xbf72,
0xb117,0x5b1b,0x31ed,0x3f88,
0xde67,0xe33f,0x5779,0x3fa2,
0x87c2,0x9d42,0x071a,0xbfce,
0x3c51,0xc9cd,0x4944,0x3fb2,
0x0000,0x0000,0x0000,0x3ff0
};
#define MAXGAM 171.624376956302725
#endif
#ifdef MIEEE
static const unsigned short P[] = {
0x3f24,0xfcb8,0x3998,0x2153,
0x3f53,0x84e3,0xe686,0xbfab,
0x3f85,0x57cd,0xe9db,0x14b0,
0x3fa8,0x63d9,0x18c4,0x23d3,
0x3fca,0x8da9,0xdcae,0x7d31,
0x3fdf,0xa137,0x3993,0xe312,
0x3ff0,0x0000,0x0000,0x0000
};
static const unsigned short Q[] = {
0xbef8,0x487a,0x8400,0xd3af,
0x3f41,0xae8a,0x2915,0x2573,
0xbf72,0x40e4,0xe750,0xb44a,
0x3f88,0x31ed,0x5b1b,0xb117,
0x3fa2,0x5779,0xe33f,0xde67,
0xbfce,0x071a,0x9d42,0x87c2,
0x3fb2,0x4944,0xc9cd,0x3c51,
0x3ff0,0x0000,0x0000,0x0000
};
#define MAXGAM 171.624376956302725
#endif
/* Stirling's formula for the gamma function */
#if UNK
static const double STIR[5] = {
7.87311395793093628397E-4,
-2.29549961613378126380E-4,
-2.68132617805781232825E-3,
3.47222221605458667310E-3,
8.33333333333482257126E-2,
};
#define MAXSTIR 143.01608
static const double SQTPI = 2.50662827463100050242E0;
#endif
#if DEC
static const unsigned short STIR[20] = {
0035516,0061622,0144553,0112224,
0135160,0131531,0037460,0165740,
0136057,0134460,0037242,0077270,
0036143,0107070,0156306,0027751,
0037252,0125252,0125252,0146064,
};
#define MAXSTIR 26.77
static const unsigned short SQT[4] = {
0040440,0066230,0177661,0034055,
};
#define SQTPI *(double *)SQT
#endif
#if IBMPC
static const unsigned short STIR[20] = {
0x7293,0x592d,0xcc72,0x3f49,
0x1d7c,0x27e6,0x166b,0xbf2e,
0x4fd7,0x07d4,0xf726,0xbf65,
0xc5fd,0x1b98,0x71c7,0x3f6c,
0x5986,0x5555,0x5555,0x3fb5,
};
#define MAXSTIR 143.01608
static const unsigned short SQT[4] = {
0x2706,0x1ff6,0x0d93,0x4004,
};
#define SQTPI *(double *)SQT
#endif
#if MIEEE
static const unsigned short STIR[20] = {
0x3f49,0xcc72,0x592d,0x7293,
0xbf2e,0x166b,0x27e6,0x1d7c,
0xbf65,0xf726,0x07d4,0x4fd7,
0x3f6c,0x71c7,0x1b98,0xc5fd,
0x3fb5,0x5555,0x5555,0x5986,
};
#define MAXSTIR 143.01608
static const unsigned short SQT[4] = {
0x4004,0x0d93,0x1ff6,0x2706,
};
#define SQTPI *(double *)SQT
#endif
#ifndef __MINGW32__
int sgngam = 0;
extern int sgngam;
extern double MAXLOG, MAXNUM, PI;
#ifdef ANSIPROT
extern double pow ( double, double );
extern double log ( double );
extern double exp ( double );
extern double sin ( double );
extern double polevl ( double, void *, int );
extern double p1evl ( double, void *, int );
extern double floor ( double );
extern double fabs ( double );
extern int isnan ( double );
extern int isfinite ( double );
static double stirf ( double );
double lgam ( double );
#else
double pow(), log(), exp(), sin(), polevl(), p1evl(), floor(), fabs();
int isnan(), isfinite();
static double stirf();
double lgam();
#endif
#ifdef INFINITIES
extern double INFINITY;
#endif
#ifdef NANS
extern double NAN;
#endif
#else /* __MINGW32__ */
static double stirf ( double );
#endif
/* Gamma function computed by Stirling's formula.
* The polynomial STIR is valid for 33 <= x <= 172.
*/
static double stirf(x)
double x;
{
double y, w, v;
w = 1.0/x;
w = 1.0 + w * polevl( w, STIR, 4 );
y = exp(x);
if( x > MAXSTIR )
{ /* Avoid overflow in pow() */
v = pow( x, 0.5 * x - 0.25 );
y = v * (v / y);
}
else
{
y = pow( x, x - 0.5 ) / y;
}
y = SQTPI * y * w;
return( y );
}
double __tgamma_r(double x, int* sgngam)
{
double p, q, z;
int i;
*sgngam = 1;
#ifdef NANS
if( isnan(x) )
return(x);
#endif
#ifdef INFINITIES
#ifdef NANS
if( x == INFINITY )
return(x);
if( x == -INFINITY )
return(NAN);
#else
if( !isfinite(x) )
return(x);
#endif
#endif
q = fabs(x);
if( q > 33.0 )
{
if( x < 0.0 )
{
p = floor(q);
if( p == q )
{
gsing:
_SET_ERRNO(EDOM);
mtherr( "tgamma", SING );
#ifdef INFINITIES
return (INFINITY);
#else
return (MAXNUM);
#endif
}
i = p;
if( (i & 1) == 0 )
*sgngam = -1;
z = q - p;
if( z > 0.5 )
{
p += 1.0;
z = q - p;
}
z = q * sin( PI * z );
if( z == 0.0 )
{
_SET_ERRNO(ERANGE);
mtherr( "tgamma", OVERFLOW );
#ifdef INFINITIES
return( *sgngam * INFINITY);
#else
return( *sgngam * MAXNUM);
#endif
}
z = fabs(z);
z = PI/(z * stirf(q) );
}
else
{
z = stirf(x);
}
return( *sgngam * z );
}
z = 1.0;
while( x >= 3.0 )
{
x -= 1.0;
z *= x;
}
while( x < 0.0 )
{
if( x > -1.E-9 )
goto small;
z /= x;
x += 1.0;
}
while( x < 2.0 )
{
if( x < 1.e-9 )
goto small;
z /= x;
x += 1.0;
}
if( x == 2.0 )
return(z);
x -= 2.0;
p = polevl( x, P, 6 );
q = polevl( x, Q, 7 );
return( z * p / q );
small:
if( x == 0.0 )
{
goto gsing;
}
else
return( z/((1.0 + 0.5772156649015329 * x) * x) );
}
/* This is the C99 version */
double tgamma(double x)
{
int local_sgngam=0;
return (__tgamma_r(x, &local_sgngam));
}

View File

@ -0,0 +1,265 @@
/* gammaf.c
*
* Gamma function
*
*
*
* SYNOPSIS:
*
* float x, y, __tgammaf_r();
* int* sgngamf;
* y = __tgammaf_r( x, sgngamf );
*
* float x, y, tgammaf();
* y = tgammaf( x);
*
*
* DESCRIPTION:
*
* Returns gamma function of the argument. The result is
* correctly signed. In the reentrant version the sign (+1 or -1)
* is returned in the variable referenced by sgngamf.
*
* Arguments between 0 and 10 are reduced by recurrence and the
* function is approximated by a polynomial function covering
* the interval (2,3). Large arguments are handled by Stirling's
* formula. Negative arguments are made positive using
* a reflection formula.
*
*
* ACCURACY:
*
* Relative error:
* arithmetic domain # trials peak rms
* IEEE 0,-33 100,000 5.7e-7 1.0e-7
* IEEE -33,0 100,000 6.1e-7 1.2e-7
*
*
*/
/*
Cephes Math Library Release 2.7: July, 1998
Copyright 1984, 1987, 1989, 1992, 1998 by Stephen L. Moshier
*/
/*
* 26-11-2002 Modified for mingw.
* Danny Smith <dannysmith@users.sourceforge.net>
*/
#ifndef __MINGW32__
#include "mconf.h"
#else
#include "cephes_mconf.h"
#endif
/* define MAXGAM 34.84425627277176174 */
/* Stirling's formula for the gamma function
* gamma(x) = sqrt(2 pi) x^(x-.5) exp(-x) ( 1 + 1/x P(1/x) )
* .028 < 1/x < .1
* relative error < 1.9e-11
*/
static const float STIR[] = {
-2.705194986674176E-003,
3.473255786154910E-003,
8.333331788340907E-002,
};
static const float MAXSTIR = 26.77;
static const float SQTPIF = 2.50662827463100050242; /* sqrt( 2 pi ) */
#ifndef __MINGW32__
extern float MAXLOGF, MAXNUMF, PIF;
#ifdef ANSIC
float expf(float);
float logf(float);
float powf( float, float );
float sinf(float);
float gammaf(float);
float floorf(float);
static float stirf(float);
float polevlf( float, float *, int );
float p1evlf( float, float *, int );
#else
float expf(), logf(), powf(), sinf(), floorf();
float polevlf(), p1evlf();
static float stirf();
#endif
#else /* __MINGW32__ */
static float stirf(float);
#endif
/* Gamma function computed by Stirling's formula,
* sqrt(2 pi) x^(x-.5) exp(-x) (1 + 1/x P(1/x))
* The polynomial STIR is valid for 33 <= x <= 172.
*/
static float stirf( float x )
{
float y, w, v;
w = 1.0/x;
w = 1.0 + w * polevlf( w, STIR, 2 );
y = expf( -x );
if( x > MAXSTIR )
{ /* Avoid overflow in pow() */
v = powf( x, 0.5 * x - 0.25 );
y *= v;
y *= v;
}
else
{
y = powf( x, x - 0.5 ) * y;
}
y = SQTPIF * y * w;
return( y );
}
/* gamma(x+2), 0 < x < 1 */
static const float P[] = {
1.536830450601906E-003,
5.397581592950993E-003,
4.130370201859976E-003,
7.232307985516519E-002,
8.203960091619193E-002,
4.117857447645796E-001,
4.227867745131584E-001,
9.999999822945073E-001,
};
float __tgammaf_r( float x, int* sgngamf)
{
float p, q, z, nz;
int i, direction, negative;
#ifdef NANS
if( isnan(x) )
return(x);
#endif
#ifdef INFINITIES
#ifdef NANS
if( x == INFINITYF )
return(x);
if( x == -INFINITYF )
return(NANF);
#else
if( !isfinite(x) )
return(x);
#endif
#endif
*sgngamf = 1;
negative = 0;
nz = 0.0;
if( x < 0.0 )
{
negative = 1;
q = -x;
p = floorf(q);
if( p == q )
{
gsing:
_SET_ERRNO(EDOM);
mtherr( "tgammaf", SING );
#ifdef INFINITIES
return (INFINITYF);
#else
return (MAXNUMF);
#endif
}
i = p;
if( (i & 1) == 0 )
*sgngamf = -1;
nz = q - p;
if( nz > 0.5 )
{
p += 1.0;
nz = q - p;
}
nz = q * sinf( PIF * nz );
if( nz == 0.0 )
{
_SET_ERRNO(ERANGE);
mtherr( "tgamma", OVERFLOW );
#ifdef INFINITIES
return( *sgngamf * INFINITYF);
#else
return( *sgngamf * MAXNUMF);
#endif
}
if( nz < 0 )
nz = -nz;
x = q;
}
if( x >= 10.0 )
{
z = stirf(x);
}
if( x < 2.0 )
direction = 1;
else
direction = 0;
z = 1.0;
while( x >= 3.0 )
{
x -= 1.0;
z *= x;
}
/*
while( x < 0.0 )
{
if( x > -1.E-4 )
goto small;
z *=x;
x += 1.0;
}
*/
while( x < 2.0 )
{
if( x < 1.e-4 )
goto small;
z *=x;
x += 1.0;
}
if( direction )
z = 1.0/z;
if( x == 2.0 )
return(z);
x -= 2.0;
p = z * polevlf( x, P, 7 );
gdone:
if( negative )
{
p = *sgngamf * PIF/(nz * p );
}
return(p);
small:
if( x == 0.0 )
{
goto gsing;
}
else
{
p = z / ((1.0 + 0.5772156649015329 * x) * x);
goto gdone;
}
}
/* This is the C99 version */
float tgammaf(float x)
{
int local_sgngamf=0;
return (__tgammaf_r(x, &local_sgngamf));
}

View File

@ -0,0 +1,501 @@
/* gammal.c
*
* Gamma function
*
*
*
* SYNOPSIS:
*
* long double x, y, __tgammal_r();
* int* sgngaml;
* y = __tgammal_r( x, sgngaml );
*
* long double x, y, tgammal();
* y = tgammal( x); *
*
*
* DESCRIPTION:
*
* Returns gamma function of the argument. The result is
* correctly signed. In the reentrant version the sign (+1 or -1)
* is returned in the variable referenced by sgngamf.
*
* Arguments |x| <= 13 are reduced by recurrence and the function
* approximated by a rational function of degree 7/8 in the
* interval (2,3). Large arguments are handled by Stirling's
* formula. Large negative arguments are made positive using
* a reflection formula.
*
*
* ACCURACY:
*
* Relative error:
* arithmetic domain # trials peak rms
* IEEE -40,+40 10000 3.6e-19 7.9e-20
* IEEE -1755,+1755 10000 4.8e-18 6.5e-19
*
* Accuracy for large arguments is dominated by error in powl().
*
*/
/*
Copyright 1994 by Stephen L. Moshier
*/
/*
* 26-11-2002 Modified for mingw.
* Danny Smith <dannysmith@users.sourceforge.net>
*/
#ifndef __MINGW32__
#include "mconf.h"
#else
#include "cephes_mconf.h"
#endif
/*
gamma(x+2) = gamma(x+2) P(x)/Q(x)
0 <= x <= 1
Relative error
n=7, d=8
Peak error = 1.83e-20
Relative error spread = 8.4e-23
*/
#if UNK
static const long double P[8] = {
4.212760487471622013093E-5L,
4.542931960608009155600E-4L,
4.092666828394035500949E-3L,
2.385363243461108252554E-2L,
1.113062816019361559013E-1L,
3.629515436640239168939E-1L,
8.378004301573126728826E-1L,
1.000000000000000000009E0L,
};
static const long double Q[9] = {
-1.397148517476170440917E-5L,
2.346584059160635244282E-4L,
-1.237799246653152231188E-3L,
-7.955933682494738320586E-4L,
2.773706565840072979165E-2L,
-4.633887671244534213831E-2L,
-2.243510905670329164562E-1L,
4.150160950588455434583E-1L,
9.999999999999999999908E-1L,
};
#endif
#if IBMPC
static const short P[] = {
0x434a,0x3f22,0x2bda,0xb0b2,0x3ff0, XPD
0xf5aa,0xe82f,0x335b,0xee2e,0x3ff3, XPD
0xbe6c,0x3757,0xc717,0x861b,0x3ff7, XPD
0x7f43,0x5196,0xb166,0xc368,0x3ff9, XPD
0x9549,0x8eb5,0x8c3a,0xe3f4,0x3ffb, XPD
0x8d75,0x23af,0xc8e4,0xb9d4,0x3ffd, XPD
0x29cf,0x19b3,0x16c8,0xd67a,0x3ffe, XPD
0x0000,0x0000,0x0000,0x8000,0x3fff, XPD
};
static const short Q[] = {
0x5473,0x2de8,0x1268,0xea67,0xbfee, XPD
0x334b,0xc2f0,0xa2dd,0xf60e,0x3ff2, XPD
0xbeed,0x1853,0xa691,0xa23d,0xbff5, XPD
0x296e,0x7cb1,0x5dfd,0xd08f,0xbff4, XPD
0x0417,0x7989,0xd7bc,0xe338,0x3ff9, XPD
0x3295,0x3698,0xd580,0xbdcd,0xbffa, XPD
0x75ef,0x3ab7,0x4ad3,0xe5bc,0xbffc, XPD
0xe458,0x2ec7,0xfd57,0xd47c,0x3ffd, XPD
0x0000,0x0000,0x0000,0x8000,0x3fff, XPD
};
#endif
#if MIEEE
static const long P[24] = {
0x3ff00000,0xb0b22bda,0x3f22434a,
0x3ff30000,0xee2e335b,0xe82ff5aa,
0x3ff70000,0x861bc717,0x3757be6c,
0x3ff90000,0xc368b166,0x51967f43,
0x3ffb0000,0xe3f48c3a,0x8eb59549,
0x3ffd0000,0xb9d4c8e4,0x23af8d75,
0x3ffe0000,0xd67a16c8,0x19b329cf,
0x3fff0000,0x80000000,0x00000000,
};
static const long Q[27] = {
0xbfee0000,0xea671268,0x2de85473,
0x3ff20000,0xf60ea2dd,0xc2f0334b,
0xbff50000,0xa23da691,0x1853beed,
0xbff40000,0xd08f5dfd,0x7cb1296e,
0x3ff90000,0xe338d7bc,0x79890417,
0xbffa0000,0xbdcdd580,0x36983295,
0xbffc0000,0xe5bc4ad3,0x3ab775ef,
0x3ffd0000,0xd47cfd57,0x2ec7e458,
0x3fff0000,0x80000000,0x00000000,
};
#endif
/*
static const long double P[] = {
-3.01525602666895735709e0L,
-3.25157411956062339893e1L,
-2.92929976820724030353e2L,
-1.70730828800510297666e3L,
-7.96667499622741999770e3L,
-2.59780216007146401957e4L,
-5.99650230220855581642e4L,
-7.15743521530849602425e4L
};
static const long double Q[] = {
1.00000000000000000000e0L,
-1.67955233807178858919e1L,
8.85946791747759881659e1L,
5.69440799097468430177e1L,
-1.98526250512761318471e3L,
3.31667508019495079814e3L,
1.60577839621734713377e4L,
-2.97045081369399940529e4L,
-7.15743521530849602412e4L
};
*/
#define MAXGAML 1755.455L
/*static const long double LOGPI = 1.14472988584940017414L;*/
/* Stirling's formula for the gamma function
gamma(x) = sqrt(2 pi) x^(x-.5) exp(-x) (1 + 1/x P(1/x))
z(x) = x
13 <= x <= 1024
Relative error
n=8, d=0
Peak error = 9.44e-21
Relative error spread = 8.8e-4
*/
#if UNK
static const long double STIR[9] = {
7.147391378143610789273E-4L,
-2.363848809501759061727E-5L,
-5.950237554056330156018E-4L,
6.989332260623193171870E-5L,
7.840334842744753003862E-4L,
-2.294719747873185405699E-4L,
-2.681327161876304418288E-3L,
3.472222222230075327854E-3L,
8.333333333333331800504E-2L,
};
#endif
#if IBMPC
static const short STIR[] = {
0x6ede,0x69f7,0x54e3,0xbb5d,0x3ff4, XPD
0xc395,0x0295,0x4443,0xc64b,0xbfef, XPD
0xba6f,0x7c59,0x5e47,0x9bfb,0xbff4, XPD
0x5704,0x1a39,0xb11d,0x9293,0x3ff1, XPD
0x30b7,0x1a21,0x98b2,0xcd87,0x3ff4, XPD
0xbef3,0x7023,0x6a08,0xf09e,0xbff2, XPD
0x3a1c,0x5ac8,0x3478,0xafb9,0xbff6, XPD
0xc3c9,0x906e,0x38e3,0xe38e,0x3ff6, XPD
0xa1d5,0xaaaa,0xaaaa,0xaaaa,0x3ffb, XPD
};
#endif
#if MIEEE
static const long STIR[27] = {
0x3ff40000,0xbb5d54e3,0x69f76ede,
0xbfef0000,0xc64b4443,0x0295c395,
0xbff40000,0x9bfb5e47,0x7c59ba6f,
0x3ff10000,0x9293b11d,0x1a395704,
0x3ff40000,0xcd8798b2,0x1a2130b7,
0xbff20000,0xf09e6a08,0x7023bef3,
0xbff60000,0xafb93478,0x5ac83a1c,
0x3ff60000,0xe38e38e3,0x906ec3c9,
0x3ffb0000,0xaaaaaaaa,0xaaaaa1d5,
};
#endif
#define MAXSTIR 1024.0L
static const long double SQTPI = 2.50662827463100050242E0L;
/* 1/gamma(x) = z P(z)
* z(x) = 1/x
* 0 < x < 0.03125
* Peak relative error 4.2e-23
*/
#if UNK
static const long double S[9] = {
-1.193945051381510095614E-3L,
7.220599478036909672331E-3L,
-9.622023360406271645744E-3L,
-4.219773360705915470089E-2L,
1.665386113720805206758E-1L,
-4.200263503403344054473E-2L,
-6.558780715202540684668E-1L,
5.772156649015328608253E-1L,
1.000000000000000000000E0L,
};
#endif
#if IBMPC
static const unsigned short S[] = {
0xbaeb,0xd6d3,0x25e5,0x9c7e,0xbff5, XPD
0xfe9a,0xceb4,0xc74e,0xec9a,0x3ff7, XPD
0x9225,0xdfef,0xb0e9,0x9da5,0xbff8, XPD
0x10b0,0xec17,0x87dc,0xacd7,0xbffa, XPD
0x6b8d,0x7515,0x1905,0xaa89,0x3ffc, XPD
0xf183,0x126b,0xf47d,0xac0a,0xbffa, XPD
0x7bf6,0x57d1,0xa013,0xa7e7,0xbffe, XPD
0xc7a9,0x7db0,0x67e3,0x93c4,0x3ffe, XPD
0x0000,0x0000,0x0000,0x8000,0x3fff, XPD
};
#endif
#if MIEEE
static const long S[27] = {
0xbff50000,0x9c7e25e5,0xd6d3baeb,
0x3ff70000,0xec9ac74e,0xceb4fe9a,
0xbff80000,0x9da5b0e9,0xdfef9225,
0xbffa0000,0xacd787dc,0xec1710b0,
0x3ffc0000,0xaa891905,0x75156b8d,
0xbffa0000,0xac0af47d,0x126bf183,
0xbffe0000,0xa7e7a013,0x57d17bf6,
0x3ffe0000,0x93c467e3,0x7db0c7a9,
0x3fff0000,0x80000000,0x00000000,
};
#endif
/* 1/gamma(-x) = z P(z)
* z(x) = 1/x
* 0 < x < 0.03125
* Peak relative error 5.16e-23
* Relative error spread = 2.5e-24
*/
#if UNK
static const long double SN[9] = {
1.133374167243894382010E-3L,
7.220837261893170325704E-3L,
9.621911155035976733706E-3L,
-4.219773343731191721664E-2L,
-1.665386113944413519335E-1L,
-4.200263503402112910504E-2L,
6.558780715202536547116E-1L,
5.772156649015328608727E-1L,
-1.000000000000000000000E0L,
};
#endif
#if IBMPC
static const unsigned short SN[] = {
0x5dd1,0x02de,0xb9f7,0x948d,0x3ff5, XPD
0x989b,0xdd68,0xc5f1,0xec9c,0x3ff7, XPD
0x2ca1,0x18f0,0x386f,0x9da5,0x3ff8, XPD
0x783f,0x41dd,0x87d1,0xacd7,0xbffa, XPD
0x7a5b,0xd76d,0x1905,0xaa89,0xbffc, XPD
0x7f64,0x1234,0xf47d,0xac0a,0xbffa, XPD
0x5e26,0x57d1,0xa013,0xa7e7,0x3ffe, XPD
0xc7aa,0x7db0,0x67e3,0x93c4,0x3ffe, XPD
0x0000,0x0000,0x0000,0x8000,0xbfff, XPD
};
#endif
#if MIEEE
static const long SN[27] = {
0x3ff50000,0x948db9f7,0x02de5dd1,
0x3ff70000,0xec9cc5f1,0xdd68989b,
0x3ff80000,0x9da5386f,0x18f02ca1,
0xbffa0000,0xacd787d1,0x41dd783f,
0xbffc0000,0xaa891905,0xd76d7a5b,
0xbffa0000,0xac0af47d,0x12347f64,
0x3ffe0000,0xa7e7a013,0x57d15e26,
0x3ffe0000,0x93c467e3,0x7db0c7aa,
0xbfff0000,0x80000000,0x00000000,
};
#endif
#ifndef __MINGW32__
extern long double MAXLOGL, MAXNUML, PIL;
/* #define PIL 3.14159265358979323846L */
/* #define MAXNUML 1.189731495357231765021263853E4932L */
#ifdef ANSIPROT
extern long double fabsl ( long double );
extern long double lgaml ( long double );
extern long double logl ( long double );
extern long double expl ( long double );
extern long double gammal ( long double );
extern long double sinl ( long double );
extern long double floorl ( long double );
extern long double powl ( long double, long double );
extern long double polevll ( long double, void *, int );
extern long double p1evll ( long double, void *, int );
extern int isnanl ( long double );
extern int isfinitel ( long double );
static long double stirf ( long double );
#else
long double fabsl(), lgaml(), logl(), expl(), gammal(), sinl();
long double floorl(), powl(), polevll(), p1evll(), isnanl(), isfinitel();
static long double stirf();
#endif
#ifdef INFINITIES
extern long double INFINITYL;
#endif
#ifdef NANS
extern long double NANL;
#endif
#else /* __MINGW32__ */
static long double stirf ( long double );
#endif
/* Gamma function computed by Stirling's formula. */
static long double stirf(x)
long double x;
{
long double y, w, v;
w = 1.0L/x;
/* For large x, use rational coefficients from the analytical expansion. */
if( x > 1024.0L )
w = (((((6.97281375836585777429E-5L * w
+ 7.84039221720066627474E-4L) * w
- 2.29472093621399176955E-4L) * w
- 2.68132716049382716049E-3L) * w
+ 3.47222222222222222222E-3L) * w
+ 8.33333333333333333333E-2L) * w
+ 1.0L;
else
w = 1.0L + w * polevll( w, STIR, 8 );
y = expl(x);
if( x > MAXSTIR )
{ /* Avoid overflow in pow() */
v = powl( x, 0.5L * x - 0.25L );
y = v * (v / y);
}
else
{
y = powl( x, x - 0.5L ) / y;
}
y = SQTPI * y * w;
return( y );
}
long double __tgammal_r(long double x, int* sgngaml)
{
long double p, q, z;
int i;
*sgngaml = 1;
#ifdef NANS
if( isnanl(x) )
return(NANL);
#endif
#ifdef INFINITIES
#ifdef NANS
if( x == INFINITYL )
return(x);
if( x == -INFINITYL )
return(NANL);
#else
if( !isfinite(x) )
return(x);
#endif
#endif
q = fabsl(x);
if( q > 13.0L )
{
if( q > MAXGAML )
goto goverf;
if( x < 0.0L )
{
p = floorl(q);
if( p == q )
{
gsing:
_SET_ERRNO(EDOM);
mtherr( "tgammal", SING );
#ifdef INFINITIES
return (INFINITYL);
#else
return( *sgngaml * MAXNUML);
#endif
}
i = p;
if( (i & 1) == 0 )
*sgngaml = -1;
z = q - p;
if( z > 0.5L )
{
p += 1.0L;
z = q - p;
}
z = q * sinl( PIL * z );
z = fabsl(z) * stirf(q);
if( z <= PIL/MAXNUML )
{
goverf:
_SET_ERRNO(ERANGE);
mtherr( "tgammal", OVERFLOW );
#ifdef INFINITIES
return( *sgngaml * INFINITYL);
#else
return( *sgngaml * MAXNUML);
#endif
}
z = PIL/z;
}
else
{
z = stirf(x);
}
return( *sgngaml * z );
}
z = 1.0L;
while( x >= 3.0L )
{
x -= 1.0L;
z *= x;
}
while( x < -0.03125L )
{
z /= x;
x += 1.0L;
}
if( x <= 0.03125L )
goto small;
while( x < 2.0L )
{
z /= x;
x += 1.0L;
}
if( x == 2.0L )
return(z);
x -= 2.0L;
p = polevll( x, P, 7 );
q = polevll( x, Q, 8 );
return( z * p / q );
small:
if( x == 0.0L )
{
goto gsing;
}
else
{
if( x < 0.0L )
{
x = -x;
q = z / (x * polevll( x, SN, 8 ));
}
else
q = z / (x * polevll( x, S, 8 ));
}
return q;
}
/* This is the C99 version. */
long double tgammal(long double x)
{
int local_sgngaml=0;
return (__tgammal_r(x, &local_sgngaml));
}