From 7ce331c01ce6eb7b3f5c715a38a24359da9c6ee2 Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Thu, 22 Nov 2001 14:04:29 +0000 Subject: Totally rework the math library, this time based on the MacOs X math library (which is itself based on the math lib from FreeBSD). -Erik --- libm/float/spencef.c | 135 --------------------------------------------------- 1 file changed, 135 deletions(-) delete mode 100644 libm/float/spencef.c (limited to 'libm/float/spencef.c') diff --git a/libm/float/spencef.c b/libm/float/spencef.c deleted file mode 100644 index 52799babe..000000000 --- a/libm/float/spencef.c +++ /dev/null @@ -1,135 +0,0 @@ -/* spencef.c - * - * Dilogarithm - * - * - * - * SYNOPSIS: - * - * float x, y, spencef(); - * - * y = spencef( x ); - * - * - * - * DESCRIPTION: - * - * Computes the integral - * - * x - * - - * | | log t - * spence(x) = - | ----- dt - * | | t - 1 - * - - * 1 - * - * for x >= 0. A rational approximation gives the integral in - * the interval (0.5, 1.5). Transformation formulas for 1/x - * and 1-x are employed outside the basic expansion range. - * - * - * - * ACCURACY: - * - * Relative error: - * arithmetic domain # trials peak rms - * IEEE 0,4 30000 4.4e-7 6.3e-8 - * - * - */ - -/* spence.c */ - - -/* -Cephes Math Library Release 2.1: January, 1989 -Copyright 1985, 1987, 1989 by Stephen L. Moshier -Direct inquiries to 30 Frost Street, Cambridge, MA 02140 -*/ - -#include - -static float A[8] = { - 4.65128586073990045278E-5, - 7.31589045238094711071E-3, - 1.33847639578309018650E-1, - 8.79691311754530315341E-1, - 2.71149851196553469920E0, - 4.25697156008121755724E0, - 3.29771340985225106936E0, - 1.00000000000000000126E0, -}; -static float B[8] = { - 6.90990488912553276999E-4, - 2.54043763932544379113E-2, - 2.82974860602568089943E-1, - 1.41172597751831069617E0, - 3.63800533345137075418E0, - 5.03278880143316990390E0, - 3.54771340985225096217E0, - 9.99999999999999998740E-1, -}; - -extern float PIF, MACHEPF; - -/* pi * pi / 6 */ -#define PIFS 1.64493406684822643647 - - -float logf(float), polevlf(float, float *, int); -float spencef(float xx) -{ -float x, w, y, z; -int flag; - -x = xx; -if( x < 0.0 ) - { - mtherr( "spencef", DOMAIN ); - return(0.0); - } - -if( x == 1.0 ) - return( 0.0 ); - -if( x == 0.0 ) - return( PIFS ); - -flag = 0; - -if( x > 2.0 ) - { - x = 1.0/x; - flag |= 2; - } - -if( x > 1.5 ) - { - w = (1.0/x) - 1.0; - flag |= 2; - } - -else if( x < 0.5 ) - { - w = -x; - flag |= 1; - } - -else - w = x - 1.0; - - -y = -w * polevlf( w, A, 7) / polevlf( w, B, 7 ); - -if( flag & 1 ) - y = PIFS - logf(x) * logf(1.0-x) - y; - -if( flag & 2 ) - { - z = logf(x); - y = -0.5 * z * z - y; - } - -return( y ); -} -- cgit v1.2.3