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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/double/atanh.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/double/atanh.c')
-rw-r--r--libm/double/atanh.c156
1 files changed, 0 insertions, 156 deletions
diff --git a/libm/double/atanh.c b/libm/double/atanh.c
deleted file mode 100644
index 7bb742d3d..000000000
--- a/libm/double/atanh.c
+++ /dev/null
@@ -1,156 +0,0 @@
-/* atanh.c
- *
- * Inverse hyperbolic tangent
- *
- *
- *
- * SYNOPSIS:
- *
- * double x, y, atanh();
- *
- * y = atanh( x );
- *
- *
- *
- * DESCRIPTION:
- *
- * Returns inverse hyperbolic tangent of argument in the range
- * MINLOG to MAXLOG.
- *
- * If |x| < 0.5, the rational form x + x**3 P(x)/Q(x) is
- * employed. Otherwise,
- * atanh(x) = 0.5 * log( (1+x)/(1-x) ).
- *
- *
- *
- * ACCURACY:
- *
- * Relative error:
- * arithmetic domain # trials peak rms
- * DEC -1,1 50000 2.4e-17 6.4e-18
- * IEEE -1,1 30000 1.9e-16 5.2e-17
- *
- */
-
-/* atanh.c */
-
-
-/*
-Cephes Math Library Release 2.8: June, 2000
-Copyright (C) 1987, 1995, 2000 by Stephen L. Moshier
-*/
-
-#include <math.h>
-
-#ifdef UNK
-static double P[] = {
--8.54074331929669305196E-1,
- 1.20426861384072379242E1,
--4.61252884198732692637E1,
- 6.54566728676544377376E1,
--3.09092539379866942570E1
-};
-static double Q[] = {
-/* 1.00000000000000000000E0,*/
--1.95638849376911654834E1,
- 1.08938092147140262656E2,
--2.49839401325893582852E2,
- 2.52006675691344555838E2,
--9.27277618139601130017E1
-};
-#endif
-#ifdef DEC
-static unsigned short P[] = {
-0140132,0122235,0105775,0130300,
-0041100,0127327,0124407,0034722,
-0141470,0100113,0115607,0130535,
-0041602,0164721,0003257,0013673,
-0141367,0043046,0166673,0045750
-};
-static unsigned short Q[] = {
-/*0040200,0000000,0000000,0000000,*/
-0141234,0101326,0015460,0134564,
-0041731,0160115,0116451,0032045,
-0142171,0153343,0000532,0167226,
-0042174,0000665,0077604,0000310,
-0141671,0072235,0031114,0074377
-};
-#endif
-
-#ifdef IBMPC
-static unsigned short P[] = {
-0xb618,0xb17f,0x5493,0xbfeb,
-0xe73a,0xf520,0x15da,0x4028,
-0xf62c,0x7370,0x1009,0xc047,
-0xe2f7,0x20d5,0x5d3a,0x4050,
-0x697d,0xddb7,0xe8c4,0xc03e
-};
-static unsigned short Q[] = {
-/*0x0000,0x0000,0x0000,0x3ff0,*/
-0x172f,0xc366,0x905a,0xc033,
-0x2685,0xb3a5,0x3c09,0x405b,
-0x5dd3,0x602b,0x3adc,0xc06f,
-0x8019,0xaff0,0x8036,0x406f,
-0x8f20,0xa649,0x2e93,0xc057
-};
-#endif
-
-#ifdef MIEEE
-static unsigned short P[] = {
-0xbfeb,0x5493,0xb17f,0xb618,
-0x4028,0x15da,0xf520,0xe73a,
-0xc047,0x1009,0x7370,0xf62c,
-0x4050,0x5d3a,0x20d5,0xe2f7,
-0xc03e,0xe8c4,0xddb7,0x697d
-};
-static unsigned short Q[] = {
-0xc033,0x905a,0xc366,0x172f,
-0x405b,0x3c09,0xb3a5,0x2685,
-0xc06f,0x3adc,0x602b,0x5dd3,
-0x406f,0x8036,0xaff0,0x8019,
-0xc057,0x2e93,0xa649,0x8f20
-};
-#endif
-
-#ifdef ANSIPROT
-extern double fabs ( double );
-extern double log ( double x );
-extern double polevl ( double x, void *P, int N );
-extern double p1evl ( double x, void *P, int N );
-#else
-double fabs(), log(), polevl(), p1evl();
-#endif
-extern double INFINITY, NAN;
-
-double atanh(x)
-double x;
-{
-double s, z;
-
-#ifdef MINUSZERO
-if( x == 0.0 )
- return(x);
-#endif
-z = fabs(x);
-if( z >= 1.0 )
- {
- if( x == 1.0 )
- return( INFINITY );
- if( x == -1.0 )
- return( -INFINITY );
- mtherr( "atanh", DOMAIN );
- return( NAN );
- }
-
-if( z < 1.0e-7 )
- return(x);
-
-if( z < 0.5 )
- {
- z = x * x;
- s = x + x * z * (polevl(z, P, 4) / p1evl(z, Q, 5));
- return(s);
- }
-
-return( 0.5 * log((1.0+x)/(1.0-x)) );
-}