File:  [gforth] / gforth / engine / atanh.c
Revision 1.3: download - view: text, annotated - select for diffs
Sat Sep 23 15:47:06 2000 UTC (19 years, 2 months ago) by anton
Branches: MAIN
CVS tags: v0-5-0, HEAD
changed FSF address in copyright messages

    1: /* replacement for asinh, acosh, and atanh */
    2: 
    3: /* 
    4:   Copyright (C) 1996 Free Software Foundation, Inc.
    5: 
    6:   This file is part of Gforth.
    7: 
    8:   Gforth is free software; you can redistribute it and/or
    9:   modify it under the terms of the GNU General Public License
   10:   as published by the Free Software Foundation; either version 2
   11:   of the License, or (at your option) any later version.
   12: 
   13:   This program is distributed in the hope that it will be useful,
   14:   but WITHOUT ANY WARRANTY; without even the implied warranty of
   15:   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   16:   GNU General Public License for more details.
   17: 
   18:   You should have received a copy of the GNU General Public License
   19:   along with this program; if not, write to the Free Software
   20:   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
   21: */
   22: 
   23: #include <math.h>
   24: 
   25: double atanh(double r1)
   26: {
   27:   double r2=r1 < 0 ? -r1 : r1;
   28:   double r3=log((r2/(1.0-r2)*2)+1)/2;
   29: 
   30:   return r1 < 0 ? -r3 : r3;
   31:   /* fdup f0< >r fabs 1. d>f fover f- f/  f2* flnp1 f2/
   32:      r> IF  fnegate  THEN ;
   33:      */
   34: }
   35: 
   36: double asinh(double r1)
   37: {
   38:   return atanh(r1/sqrt(1.0+r1*r1));
   39:   /* fdup fdup f* 1. d>f f+ fsqrt f/ fatanh ; */
   40: }
   41: 
   42: double acosh(double r1)
   43: {
   44:   return(log(r1+sqrt(r1*r1-1.0)));
   45:   /* fdup fdup f* 1. d>f f- fsqrt f+ fln ; */
   46: }

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