fmod

, fmodf

, fmodl

- floating-point remainder value function

Synopsis

c99 [ flag... ] file... -lm [ library... ]
#include <math.h>

double fmod(double x, double y);

float fmodf(float x, float y);

long double fmodl(long double x, long double y);

Description

These functions return the floating-point remainder of the division of x by y.

Return Values

These functions return the value x - i * y, for some integer i such that, if y is non-zero, the result has the same sign as x and magnitude less than the magnitude of y.

If x or y is NaN, a NaN is returned.

If y is 0, a domain error occurs and a NaN is returned.

If x is infinite, a domain error occurs and a NaN is returned.

If x is ±0 and y is not 0, ±0 is returned.

If x is not infinite and y is ±Inf, x is returned.

Errors

These functions will fail if:

Domain Error

The x argument is infinite or y is 0.

If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the invalid floating-point exception is raised.

Usage

An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. An application should either examine the return value or check the floating point exception flags to detect exceptions.

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

feclearexcept(3M), fetestexcept(3M), isnan(3M), math.h(3HEAD), attributes(5), standards(5)