93 lines
1.7 KiB
C
93 lines
1.7 KiB
C
|
|
/* @(#)z_floor.c 1.0 98/08/13 */
|
|
|
|
/*
|
|
FUNCTION
|
|
<<floor>>, <<floorf>>, <<ceil>>, <<ceilf>>---floor and ceiling
|
|
INDEX
|
|
floor
|
|
INDEX
|
|
floorf
|
|
INDEX
|
|
ceil
|
|
INDEX
|
|
ceilf
|
|
|
|
ANSI_SYNOPSIS
|
|
#include <math.h>
|
|
double floor(double <[x]>);
|
|
float floorf(float <[x]>);
|
|
double ceil(double <[x]>);
|
|
float ceilf(float <[x]>);
|
|
|
|
TRAD_SYNOPSIS
|
|
#include <math.h>
|
|
double floor(<[x]>)
|
|
double <[x]>;
|
|
float floorf(<[x]>)
|
|
float <[x]>;
|
|
double ceil(<[x]>)
|
|
double <[x]>;
|
|
float ceilf(<[x]>)
|
|
float <[x]>;
|
|
|
|
DESCRIPTION
|
|
<<floor>> and <<floorf>> find
|
|
@tex
|
|
$\lfloor x \rfloor$,
|
|
@end tex
|
|
the nearest integer less than or equal to <[x]>.
|
|
<<ceil>> and <<ceilf>> find
|
|
@tex
|
|
$\lceil x\rceil$,
|
|
@end tex
|
|
the nearest integer greater than or equal to <[x]>.
|
|
|
|
RETURNS
|
|
<<floor>> and <<ceil>> return the integer result as a double.
|
|
<<floorf>> and <<ceilf>> return the integer result as a float.
|
|
|
|
PORTABILITY
|
|
<<floor>> and <<ceil>> are ANSI.
|
|
<<floorf>> and <<ceilf>> are extensions.
|
|
|
|
*/
|
|
|
|
/*****************************************************************
|
|
* floor
|
|
*
|
|
* Input:
|
|
* x - floating point value
|
|
*
|
|
* Output:
|
|
* Smallest integer less than x.
|
|
*
|
|
* Description:
|
|
* This routine returns the smallest integer less than x.
|
|
*
|
|
*****************************************************************/
|
|
|
|
#include "fdlibm.h"
|
|
#include "zmath.h"
|
|
|
|
#ifndef _DOUBLE_IS_32BITS
|
|
|
|
double
|
|
_DEFUN (floor, (double),
|
|
double x)
|
|
{
|
|
double f, y;
|
|
|
|
if (x > -1.0 && x < 1.0)
|
|
return (x >= 0 ? 0 : -1.0);
|
|
|
|
y = modf (x, &f);
|
|
|
|
if (y == 0.0)
|
|
return (x);
|
|
|
|
return (x >= 0 ? f : f - 1.0);
|
|
}
|
|
|
|
#endif /* _DOUBLE_IS_32BITS */
|