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authorEric Andersen <andersen@codepoet.org>2001-11-22 14:04:29 +0000
committerEric Andersen <andersen@codepoet.org>2001-11-22 14:04:29 +0000
commit7ce331c01ce6eb7b3f5c715a38a24359da9c6ee2 (patch)
tree3a7e8476e868ae15f4da1b7ce26b2db6f434468c /libm/float/spencef.c
parentc117dd5fb183afb1a4790a6f6110d88704be6bf8 (diff)
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
Diffstat (limited to 'libm/float/spencef.c')
-rw-r--r--libm/float/spencef.c135
1 files changed, 0 insertions, 135 deletions
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 <math.h>
-
-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 );
-}