fdim, fdimf, fdiml - positive difference
#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)):
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:
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).
| Interface | Attribute | Value |
| 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.
fmax(3)
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