1.20 fdim, fdimf—positive difference

Synopsis

     #include <math.h>
     double fdim(double x, double y);
     float fdimf(float x, float y);
     

Description
The fdim functions determine the positive difference between their arguments, returning:

     	x - y	if x > y, or

     	+0	if x <= y, or

     	NAN	if either argument is NAN.

A range error may occur.