FDIM(3) Linux Programmer's Manual FDIM(3)
fdim, fdimf, fdiml - positive difference
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)):
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
or cc -std=c99
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
An overflow floating-point exception (FE_OVERFLOW) is raised.
These functions do not set errno.
These functions first appeared in glibc in version 2.1.
Multithreading (see pthreads(7))
The fdim(), fdimf(), and fdiml() functions are thread-safe.
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