Python/fmod.c

   1
   2 /* Portable fmod(x, y) implementation for systems that don't have it */
   3
   4 #include "pyconfig.h"
   5
   6 #include "pyport.h"
   7 #include <errno.h>
   8
   9 double
  10 fmod(double x, double y)
  11 {
  12         double i, f;
  13
  14         if (y == 0.0) {
  15                 errno = EDOM;
  16                 return 0.0;
  17         }
  18
  19         /* return f such that x = i*y + f for some integer i
  20            such that |f| < |y| and f has the same sign as x */
  21
  22         i = floor(x/y);
  23         f = x - i*y;
  24         if ((x < 0.0) != (y < 0.0))
  25                 f = f-y;
  26         return f;
  27 }