mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-23 15:32:26 +00:00
95 lines
1.8 KiB
C
95 lines
1.8 KiB
C
|
|
/* @(#)z_acos.c 1.0 98/08/13 */
|
|
|
|
/*
|
|
FUNCTION
|
|
<<acos>>, <<acosf>>---arc cosine
|
|
|
|
INDEX
|
|
acos
|
|
INDEX
|
|
acosf
|
|
|
|
ANSI_SYNOPSIS
|
|
#include <math.h>
|
|
double acos(double <[x]>);
|
|
float acosf(float <[x]>);
|
|
|
|
TRAD_SYNOPSIS
|
|
#include <math.h>
|
|
double acos(<[x]>)
|
|
double <[x]>;
|
|
|
|
float acosf(<[x]>)
|
|
float <[x]>;
|
|
|
|
|
|
|
|
DESCRIPTION
|
|
|
|
<<acos>> computes the inverse cosine (arc cosine) of the input value.
|
|
Arguments to <<acos>> must be in the range @minus{}1 to 1.
|
|
|
|
<<acosf>> is identical to <<acos>>, except that it performs
|
|
its calculations on <<floats>>.
|
|
|
|
RETURNS
|
|
@ifnottex
|
|
<<acos>> and <<acosf>> return values in radians, in the range of 0 to pi
|
|
.
|
|
@end ifnottex
|
|
@tex
|
|
<<acos>> and <<acosf>> return values in radians, in the range of <<0>> t
|
|
o $\pi$.
|
|
@end tex
|
|
|
|
If <[x]> is not between @minus{}1 and 1, the returned value is NaN
|
|
(not a number) the global variable <<errno>> is set to <<EDOM>>, and a
|
|
<<DOMAIN error>> message is sent as standard error output.
|
|
|
|
You can modify error handling for these functions using <<matherr>>.
|
|
|
|
|
|
QUICKREF
|
|
ansi svid posix rentrant
|
|
acos y,y,y,m
|
|
acosf n,n,n,m
|
|
|
|
MATHREF
|
|
acos, [-1,1], acos(arg),,,
|
|
acos, NAN, arg,DOMAIN,EDOM
|
|
|
|
MATHREF
|
|
acosf, [-1,1], acosf(arg),,,
|
|
acosf, NAN, argf,DOMAIN,EDOM
|
|
|
|
*/
|
|
|
|
/*****************************************************************
|
|
* Arccosine
|
|
*
|
|
* Input:
|
|
* x - floating point value
|
|
*
|
|
* Output:
|
|
* arccosine of x
|
|
*
|
|
* Description:
|
|
* This routine returns the arccosine of x.
|
|
*
|
|
*****************************************************************/
|
|
|
|
#include "fdlibm.h"
|
|
#include "zmath.h"
|
|
|
|
#ifndef _DOUBLE_IS_32BITS
|
|
|
|
double
|
|
_DEFUN (acos, (double),
|
|
double x)
|
|
{
|
|
return (asine (x, 1));
|
|
}
|
|
|
|
#endif /* _DOUBLE_IS_32BITS */
|