fdim(3)                    Library Functions Manual                    fdim(3)

NAME
       fdim, fdimf, fdiml - positive difference

LIBRARY
       Math library (libm, -lm)

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);

   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.

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

       +--------------------------------------------+---------------+---------+
       |Interface                                   | Attribute     | Value   |
       +--------------------------------------------+---------------+---------+
       |fdim (), fdimf (), fdiml ()                 | Thread safety | MT-Safe |
       +--------------------------------------------+---------------+---------+
STANDARDS
       C11, POSIX.1-2008.

HISTORY
       glibc 2.1.  C99, POSIX.1-2001.

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

SEE ALSO
       fmax(3)

Linux man-pages 6.7               2023-10-31                           fdim(3)