osf1 man page for fmod

fmod(3) 						     Library Functions Manual							   fmod(3)

NAME
       fmod, drem, remainder - Compute the floating-point remainder

LIBRARY
       Math Library (libm.a)

SYNOPSIS
       #include <math.h>

       double	     fmod	 (double x, double y); float	    fmodf      (float  x, float  y); long double       fmodl	   (long double x,
       long double y); double	    drem       (double x, double y); float	   dremf       (float	x,  float   y);  long  double	     dreml
       (long  double  x,  long	double y); double	remainder  (double x, double y); float	      remainderf (float  x, float  y); long double
       remainderl  (long double x, long double y);

STANDARDS
       Interfaces documented on this reference page conform to industry standards as follows:

       fmod():	XPG4

       remainder():  XPG4-UNIX

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

DESCRIPTION
       The fmod(), fmodf(), and fmodl() functions return the remainder	r = x - n*y, where n = trunc(x/y).  The result has the same sign as x  and
       magnitude less than the magnitude of y.	The remainder is computed exactly and |r| is less than |y|.

       The  drem(), dremf(), dreml(), remainder(), remainderf(), and remainderl() functions return the remainder r = x - n*y, where n = rint(x/y).
       Additionally, if |n - x/y|=1/2, then n is even.	The remainder is computed exactly and |r| is less than or equal to |y|/2.

       The drem() and remainder() functions are aliases of each other.	The dremf(), and remainderf() functions are aliases of	each  other.   The
       dreml() and remainderl() functions are aliases of each other.

       The following table describes function behavior in response to exceptional arguments:

       ---------------------------------------------------------------------------
       Function 		       Exceptional Argument	 Routine Behavior
       ---------------------------------------------------------------------------
       fmod(),	fmodf(),     fmodl()   x = infinity		 Invalid argument
       fmod(),	fmodf(),     fmodl()   y = 0			 Invalid argument
       drem(),	dremf(),     dreml()   x = infinity		 Invalid argument
       drem(),	dremf(),     dreml()   y = 0			 Invalid argument
       remainder()		       x = infinity		 Invalid argument
       remainderf()		       x = infinity		 Invalid argument
       remainderl()		       x = infinity		 Invalid argument
       remainder()		       y = 0			 Invalid argument
       remainderf()		       y = 0			 Invalid argument
       remainderl()		       y = 0			 Invalid argument
       ---------------------------------------------------------------------------

       delim off

																	   fmod(3)