fmod, fmodf, fmodl - floating-point remainder function
Math library (
libm,
-lm)
#include <math.h>
double fmod(double x, double y);
float fmodf(float x, float y);
long double fmodl(long double x, long double y);
fmodf(),
fmodl():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
These functions compute the floating-point remainder of dividing
x by
y. The return value is
x -
n *
y, where
n
is the quotient of
x /
y, rounded toward zero to an integer.
On success, these functions return the value
x -
n*
y, for some integer
n, such
that the returned value has the same sign as
x and a magnitude less
than the magnitude of
y.
If
x or
y is a NaN, a NaN is returned.
If
x is an infinity, a domain error occurs, and a NaN is returned.
If
y is zero, a domain error occurs, and a NaN is returned.
If
x is +0 (-0), and
y is not zero, +0 (-0) is returned.
See
math_error(7) for information on how to determine whether an error
has occurred when calling these functions.
The following errors can occur:
- Domain error: x is an infinity
-
errno is set to EDOM (but see BUGS). An
invalid floating-point exception (FE_INVALID) is raised.
- Domain error: y is zero
-
errno is set to EDOM. An invalid
floating-point exception (FE_INVALID) is raised.
For an explanation of the terms used in this section, see
attributes(7).
| Interface |
Attribute |
Value |
| fmod (), fmodf (), fmodl () |
Thread safety |
MT-Safe |
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double also conforms to SVr4, 4.3BSD.
Before glibc 2.10, the glibc implementation did not set
errno to
EDOM when a domain error occurred for an infinite
x.
remainder(3)