NAME
fmod(), fmodf(), fmodl(), fmodw(), fmodq() — remainder functions
SYNOPSIS
#include <math.h>
double fmod(double x, double y);
float fmodf(float x, float y);
Itanium(R)-based System Only
long double fmodl(long double x, long double y);
extended fmodw(extended x, extended y);
quad fmodq(quad x, quad y);
DESCRIPTION
The
fmod()
function returns the floating-point remainder
(f)
of the division of
x
by
y,
where
f
has the same sign as
x,
such that
x=iy+f
for some integer
i,
and
|f| < |y|.
fmodf()
is a
float
version of
fmod();
it takes
float
arguments and returns a
float
result.
Itanium-based System Only
fmodl()
is a
long double
version of
fmod();
it takes
long double
arguments and returns a
long double
result.
fmodw()
is an
extended
version of
fmod();
it takes
extended
arguments and returns an
extended
result.
fmodq()
is equivalent to
fmodl()
on HP-UX systems.
USAGE
To use these functions compile either with the default
-Ae
option or with the
-Aa
and
-D_HPUX_SOURCE
options.
To use (for Itanium-based systems)
fmodw()
or
fmodq(),
compile also with the
-fpwidetypes
option.
To use any of these functions, make sure your program includes
<math.h>.
Link in the math library by specifying
-lm
on the compiler or linker command line.
RETURN VALUE
If
y
is ±INFINITY and
x
is not ±INFINITY,
fmod()
returns
x.
If
x
is ±zero and
y
is a nonzero number,
fmod()
returns
x.
If
x
or
y
is NaN,
fmod()
returns NaN.
If
x
is ±INFINITY
or
y
is zero,
fmod()
returns NaN and raises the invalid exception.
ERRORS
If
y
is zero or
x
is infinite,
fmod()
sets
errno
to [EDOM].
Itanium-based System
HP-UX
libm
functions on Itanium-based systems do not set
errno
by default. For
errno
setting, compile with the
+Olibmerrno
option.
STANDARDS CONFORMANCE
fmod()
: SVID3, XPG4.2, ANSI C, ISO/IEC C99
(including Annex F, ``IEC 60559 floating-point arithmetic'')
fmodf(),
fmodl()
: ISO/IEC C99 (including Annex F, ``IEC 60559 floating-point arithmetic'')
