HP-UX Reference (11i v1 05/09) - 3 Library Functions A-M (vol 6)

fabs(3M) fabs(3M)

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.

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, make sure your program includes <math.h>, and link in the math library by speci-

fying -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.