NAME    [Toc]    [Back]

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

SYNOPSIS    [Toc]    [Back]

       #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 );

LIBRARY    [Toc]    [Back]

       Math Library (libm)

STANDARDS    [Toc]    [Back]

       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    [Toc]    [Back]

       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 Argu-   Routine Behavior
                                       ment
       ---------------------------------------------------------------------
       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
       ---------------------------------------------------------------------




                                                          fmod(3)