NAME
copysign(), copysignf() — copysign functions
SYNOPSIS
#include <math.h>
double copysign(double x, double y);
float copysignf(float x, float y);
DESCRIPTION
The
copysign()
function returns
x
with its sign changed to the sign of
y.
The
copysign()
function is recommended by the IEEE-754 standard for
floating-point arithmetic. The ISO/ANSI C committee has approved the
copysign()
function for inclusion in the C9X draft standard.
copysignf()
is a
float
version of
copysign();
it takes
float
arguments and returns a
float
result.
copysignf()
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, compile either with the default
-Ae
option or with the
-Aa
and
-D_HPUX_SOURCE
options. Make sure your program includes
<math.h>.
Link in the math library by specifying
-lm
on the compiler or linker command line.
RETURN VALUE
The
copysign()
function returns a value with the magnitude of
x
and the sign of
y.
ERRORS
No errors are defined.
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