fdim - Man Page

positive difference

Synopsis

#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)):

fdimf(), fdiml():

_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

Description

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

Return Value

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.

Errors

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.

Versions

These functions first appeared in glibc in version 2.1.

Attributes

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

InterfaceAttributeValue
fdim(), fdimf(), fdiml()Thread safetyMT-Safe

Conforming to

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

Bugs

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

See Also

fmax(3)

Colophon

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Referenced By

fmax(3), fmin(3).

The man pages fdimf(3) and fdiml(3) are aliases of fdim(3).

2020-06-09 Linux Programmer's Manual