NAME
modf(), modff(), modfl(), modfw(), modfq() — decompose floating-point number
SYNOPSIS
#include <math.h>
double modf(double x, double *iptr);
HP Integrity Server Only
float modff(float x, float *iptr);
long double modfl(long double x, long double *iptr);
extended modfw(extended x, extended *iptr);
quad modfq(quad x, quad *iptr);
DESCRIPTION
The
modf()
function breaks the argument
x
into integral and fractional parts, each of which has the same sign as
the argument. It stores the integral part as a
double
in the object pointed to by
iptr.
Integrity Server Only
modff()
is a
float
version of
modf();
it takes
float
and
float *
arguments and returns a
float
result.
modfl()
is a
long double
version of
modf();
it takes
long double
and
long double *
arguments and returns a
long double
result.
modfw()
is an
extended
version of
modf();
it takes
extended
and
extended *
arguments and returns an
extended
result.
modfq()
is equivalent to
modfl()
on HP-UX systems.
USAGE
To use (for Integrity servers)
modff(),
compile either with the default
-Ae
option or with the
-Aa
option.
To use (for Integrity servers)
modfl(),
modfw(), or
modfq(),
compile either with the default
-Ae
option or with the
-Aa
and
-D_HPUX_SOURCE
options.
To use (for Integrity servers)
modfw()
or
modfq(),
compile also with the
-fpwidetypes
option.
To use these functions, make sure your program includes
<math.h>,
and link in the math library by specifying
-lm
on the compiler or linker command line.
For more information, see the
HP-UX floating-point guide for HP Integrity servers
at the following site:
http://www.hp.com/go/fp.
RETURN VALUE
modf(±x,iptr)
returns a result with the same sign as
x.
modf(±Inf,iptr)
returns ±0 and stores ±Inf
in the object pointed to by
iptr.
modf(NaN,iptr)
stores a NaN in the object pointed to by
iptr
and returns a NaN.
ERRORS
No errors are defined.
STANDARDS CONFORMANCE
modf()
: SVID3, XPG4.2, ANSI C, ISO/IEC C99
(including Annex F, ``IEC 60559 floating-point arithmetic'')
modff(),
modfl()
: ISO/IEC C99 (including Annex F, ``IEC 60559 floating-point arithmetic'')
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