mirror of
https://github.com/ZDoom/raze-gles.git
synced 2024-12-30 21:31:03 +00:00
107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
/* cosh.c
|
||
*
|
||
* Hyperbolic cosine
|
||
*
|
||
*
|
||
*
|
||
* SYNOPSIS:
|
||
*
|
||
* double x, y, cosh();
|
||
*
|
||
* y = cosh( x );
|
||
*
|
||
*
|
||
*
|
||
* DESCRIPTION:
|
||
*
|
||
* Returns hyperbolic cosine of argument in the range MINLOG to
|
||
* MAXLOG.
|
||
*
|
||
* cosh(x) = ( exp(x) + exp(-x) )/2.
|
||
*
|
||
*
|
||
*
|
||
* ACCURACY:
|
||
*
|
||
* Relative error:
|
||
* arithmetic domain # trials peak rms
|
||
* DEC +- 88 50000 4.0e-17 7.7e-18
|
||
* IEEE +-MAXLOG 30000 2.6e-16 5.7e-17
|
||
*
|
||
*
|
||
* ERROR MESSAGES:
|
||
*
|
||
* message condition value returned
|
||
* cosh overflow |x| > MAXLOG MAXNUM
|
||
*
|
||
*
|
||
*/
|
||
|
||
/* cosh.c */
|
||
|
||
/*
|
||
Cephes Math Library Release 2.8: June, 2000
|
||
Copyright 1985, 1995, 2000 by Stephen L. Moshier
|
||
|
||
Redistribution and use in source and binary forms, with or without
|
||
modification, are permitted provided that the following conditions are met:
|
||
|
||
1. Redistributions of source code must retain the above copyright notice,
|
||
this list of conditions and the following disclaimer.
|
||
2. Redistributions in binary form must reproduce the above copyright
|
||
notice, this list of conditions and the following disclaimer in the
|
||
documentation and/or other materials provided with the distribution.
|
||
3. Neither the name of the <ORGANIZATION> nor the names of its
|
||
contributors may be used to endorse or promote products derived from
|
||
this software without specific prior written permission.
|
||
|
||
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
||
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
||
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
||
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
||
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
||
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
||
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
||
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||
POSSIBILITY OF SUCH DAMAGE.
|
||
*/
|
||
|
||
#include "mconf.h"
|
||
#ifdef ANSIPROT
|
||
extern double c_exp ( double );
|
||
extern int isnan ( double );
|
||
extern int isfinite ( double );
|
||
#else
|
||
double c_exp();
|
||
int isnan(), isfinite();
|
||
#endif
|
||
extern double MAXLOG, INFINITY, LOGE2;
|
||
|
||
double c_cosh(x)
|
||
double x;
|
||
{
|
||
double y;
|
||
|
||
#ifdef NANS
|
||
if( isnan(x) )
|
||
return(x);
|
||
#endif
|
||
if( x < 0 )
|
||
x = -x;
|
||
if( x > (MAXLOG + LOGE2) )
|
||
{
|
||
mtherr( "cosh", OVERFLOW );
|
||
return( INFINITY );
|
||
}
|
||
if( x >= (MAXLOG - LOGE2) )
|
||
{
|
||
y = c_exp(0.5 * x);
|
||
y = (0.5 * y) * y;
|
||
return(y);
|
||
}
|
||
y = c_exp(x);
|
||
y = 0.5 * (y + 1.0 / y);
|
||
return( y );
|
||
}
|