fmod()                   Calculate Floating-Point Remainder
 
 #include   <math.h>                     Required for declarations only
 
 double     fmod(x,y);
 double     x;                           Floating-point dividend
 double     y;                           Floating-point divisor
 
    fmod() returns the remainder of 'x'/'y'.  The remainder (r) will have
    the same sign as 'x'; the absolute value of (r) will be less than the
    absolute value of 'y'; and the following equation will be true:
 
                       (x == i * y + r)
 
    where (i) is a signed integer and (r) is the value returned by
    fmod().
 
    Returns:    Remainder of 'x'/'y'.  If 'y' is 0.0 then 0.0 is
                returned.
 
  -------------------------------- Example ---------------------------------
 
    The following statements calculate the floating point remainders of
    -15.0 / 4.0, 6.1 / -2.5 and 5.5 / 0.0:
 
         #include <math.h>      /* Required for function definition only */
 
         main()
         {
             double x, y, z;
 
             x = fmod(-15.0, 4.0);   /* x = -3.0 */
             y = fmod(6.1, -2.5);    /* y =  1.1 */
             z = fmod(5.5, 0.0);     /* z =  0.0 */
         }

Seealso:


 ceil() 
 fabs() 
 floor()