Determines the positive difference between its arguments.

    This function is supported on OpenVMS Integrity servers and
    Alpha only.

    Format

      #include  <math.h>

      double fdim  (double x, double y);

      float fdimf  (float x, float y);

      long double fdiml  (long double x, long double y);

1 - Argument

 x

    A real value.

 y

    A real value.

2 - Description

    The fdim functions determine the positive difference between
    their arguments. If x is greater than y, x - y is returned. If x
    is less than or equal to y, +0 is returned.

3 - Return Values

    n                  Upon success, the positive difference value.
    HUGE_VAL           If x - y is positive and overflows; errno is
                       set to ERANGE.
    0                  If x - y is positive and underflows; errno is
                       set to ERANGE.
    NaN                x or y is NaN; errno is set to EDOM.