NAME
fabs(), fabsf() — absolute value functions
SYNOPSIS
#include <math.h>
double fabs(double x);
float fabsf(float x);
DESCRIPTION
The
fabs()
function returns the absolute value of
x,
|x|.
The
fabsf()
function is a
float
version of
fabs();
it takes a
float
argument and returns a
float
result.
To use this function, compile either with the default
-Ae
option or with the
-Aa
and
-D_HPUX_SOURCE
options.
Otherwise, the compiler will not find a correct declaration of
fabsf(),
and error messages or incorrect results will occur.
The
fabsf()
function is not specified by any standard, but it is
named in accordance with the conventions specified in
the "Future Library Directions" section of the
ANSI C standard.
To use these functions, link in the math library by specifying
-lm
on the compiler or linker command line.
RETURN VALUE
If
x
is ±INFINITY,
fabs()
returns +INFINITY.
If
if
x
is NaN,
fabs()
returns NaN.
If the correct value after rounding would be smaller in magnitude than
MINDOUBLE,
fabs()
returns zero.
ERRORS
No errors are defined.
STANDARDS CONFORMANCE
fabs(): SVID3, XPG4.2, ANSI C
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