File:  [gforth] / gforth / Attic / atanh.c
Revision 1.2: download - view: text, annotated - select for diffs
Sat Dec 14 14:21:19 1996 UTC (22 years, 11 months ago) by anton
Branches: MAIN
CVS tags: v0-3-0, v0-2-1, HEAD
fixed a few bugs
changed version number to 0.2.1

/* replacement for asinh, acosh, and atanh */

#include <math.h>

double atanh(double r1)
{
  double r2=r1 < 0 ? -r1 : r1;
  double r3=log((r2/(1.0-r2)*2)+1)/2;

  return r1 < 0 ? -r3 : r3;
  /* fdup f0< >r fabs 1. d>f fover f- f/  f2* flnp1 f2/
     r> IF  fnegate  THEN ;
     */
}

double asinh(double r1)
{
  return atanh(r1/sqrt(1.0+r1*r1));
  /* fdup fdup f* 1. d>f f+ fsqrt f/ fatanh ; */
}

double acosh(double r1)
{
  return(log(r1+sqrt(r1*r1-1.0)));
  /* fdup fdup f* 1. d>f f- fsqrt f+ fln ; */
}

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