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Diffstat (limited to 'libm/float/betaf.c')
-rw-r--r-- | libm/float/betaf.c | 122 |
1 files changed, 0 insertions, 122 deletions
diff --git a/libm/float/betaf.c b/libm/float/betaf.c deleted file mode 100644 index 7a1963191..000000000 --- a/libm/float/betaf.c +++ /dev/null @@ -1,122 +0,0 @@ -/* betaf.c - * - * Beta function - * - * - * - * SYNOPSIS: - * - * float a, b, y, betaf(); - * - * y = betaf( a, b ); - * - * - * - * DESCRIPTION: - * - * - - - * | (a) | (b) - * beta( a, b ) = -----------. - * - - * | (a+b) - * - * For large arguments the logarithm of the function is - * evaluated using lgam(), then exponentiated. - * - * - * - * ACCURACY: - * - * Relative error: - * arithmetic domain # trials peak rms - * IEEE 0,30 10000 4.0e-5 6.0e-6 - * IEEE -20,0 10000 4.9e-3 5.4e-5 - * - * ERROR MESSAGES: - * - * message condition value returned - * betaf overflow log(beta) > MAXLOG 0.0 - * a or b <0 integer 0.0 - * - */ - -/* beta.c */ - - -/* -Cephes Math Library Release 2.2: July, 1992 -Copyright 1984, 1987 by Stephen L. Moshier -Direct inquiries to 30 Frost Street, Cambridge, MA 02140 -*/ - -#include <math.h> - -#define fabsf(x) ( (x) < 0 ? -(x) : (x) ) - -#define MAXGAM 34.84425627277176174 - - -extern float MAXLOGF, MAXNUMF; -extern int sgngamf; - -#ifdef ANSIC -float gammaf(float), lgamf(float), expf(float), floorf(float); -#else -float gammaf(), lgamf(), expf(), floorf(); -#endif - -float betaf( float aa, float bb ) -{ -float a, b, y; -int sign; - -sign = 1; -a = aa; -b = bb; -if( a <= 0.0 ) - { - if( a == floorf(a) ) - goto over; - } -if( b <= 0.0 ) - { - if( b == floorf(b) ) - goto over; - } - - -y = a + b; -if( fabsf(y) > MAXGAM ) - { - y = lgamf(y); - sign *= sgngamf; /* keep track of the sign */ - y = lgamf(b) - y; - sign *= sgngamf; - y = lgamf(a) + y; - sign *= sgngamf; - if( y > MAXLOGF ) - { -over: - mtherr( "betaf", OVERFLOW ); - return( sign * MAXNUMF ); - } - return( sign * expf(y) ); - } - -y = gammaf(y); -if( y == 0.0 ) - goto over; - -if( a > b ) - { - y = gammaf(a)/y; - y *= gammaf(b); - } -else - { - y = gammaf(b)/y; - y *= gammaf(a); - } - -return(y); -} |