remainder(3) [osf1 man page]

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)

REMAINDER(3)						     Linux Programmer's Manual						      REMAINDER(3)

NAME

       drem, dremf, dreml, remainder, remainderf, remainderl - floating-point remainder function

SYNOPSIS

       #include <math.h>

       /* The C99 versions */
       double remainder(double x, double y);
       float remainderf(float x, float y);
       long double remainderl(long double x, long double y);

       /* Obsolete synonyms */
       double drem(double x, double y);
       float dremf(float x, float y);
       long double dreml(long double x, long double y);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       remainder(): _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 500 || _ISOC99_SOURCE; or cc -std=c99
       remainderf(), remainderl(): _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99
       drem(), dremf(), dreml(): _SVID_SOURCE || _BSD_SOURCE

DESCRIPTION

       The  remainder() function computes the remainder of dividing x by y.  The return value is x-n*y, where n is the value x / y, rounded to the
       nearest integer.  If the absolute value of x-n*y is 0.5, n is chosen to be even.

       These functions are unaffected by the current rounding mode (see fenv(3)).

       The drem() function does precisely the same thing.

RETURN VALUE

       On success, these functions return the floating-point remainder, x-n*y.	If the return value is 0, it has the sign of x.

       If x or y is a NaN, a NaN is returned.

       If x is an infinity, and y is not a NaN, a domain error occurs, and a NaN is returned.

       If y is zero, and x is not a NaN, a domain error occurs, and a NaN is returned.

ERRORS

       See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

       The following errors can occur:

       Domain error: x is an infinity and y is not a NaN
	      An invalid floating-point exception (FE_INVALID) is raised.

	      These functions do not set errno for this case.

       Domain error: y is zero
	      errno is set to EDOM.  An invalid floating-point exception (FE_INVALID) is raised.

CONFORMING TO

       The functions remainder(), remainderf(), and remainderl() are specified in C99 and POSIX.1-2001.

       The function drem() is from 4.3BSD.  The float and long double variants dremf() and dreml() exist  on  some  systems,  such  as	Tru64  and
       glibc2.	Avoid the use of these functions in favor of remainder() etc.

BUGS

       The call

	   remainder(nan(""), 0);

       returns a NaN, as expected, but wrongly causes a domain error; it should yield a silent NaN.

EXAMPLE

       The call "remainder(29.0, 3.0)" returns -1.

SEE ALSO

       div(3), fmod(3), remquo(3)

COLOPHON

       This  page is part of release 3.25 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

								    2009-02-04							      REMAINDER(3)