NAME

fdim, fdimf, fdiml - positive difference

LIBRARY

Math library (libm, -lm)

#include <math.h>

double fdim(double x, double y);
float fdimf(float x, float y);
long double fdiml(long double x, long double y);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

fdimf(), fdiml():



    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

These functions return the positive difference, max(x-y,0), between their arguments.

On success, these functions return the positive difference.

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

If the result overflows, a range error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively.

See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

The following errors can occur:

Range error: result overflow: errno is set to ERANGE. An overflow floating-point exception (FE_OVERFLOW) is raised.

These functions were added in glibc 2.1.

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
fdim (), fdimf (), fdiml ()	Thread safety	MT-Safe

C99, POSIX.1-2001, POSIX.1-2008.

Before glibc 2.24 on certain architectures (e.g., x86, but not x86_64) these functions did not set errno.