#include <math.h> double fdim(double x, double y); float fdimf(float x, float y); long double fdiml(long double x, long double y);
Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_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 first appeared in glibc in version 2.1.
For an explanation of the terms used in this section, see attributes(7).
|fdim(), fdimf(), fdiml()||Thread safety||MT-Safe|
C99, POSIX.1-2001, POSIX.1-2008.
Before glibc version 2.24 on certain architectures (e.g., x86, but not x86_64) these functions did not set errno.
This page is part of release 5.13 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
The man pages fdimf(3) and fdiml(3) are aliases of fdim(3).