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



NAME
       modf,  modff,  modfl  -  extract signed integral and fractional values from floating-point
       number

SYNOPSIS
       #include <math.h>

       double modf(double x, double *iptr);
       float modff(float x, float *iptr);
       long double modfl(long double x, long double *iptr);

       Link with -lm.

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

       modf(), modfl():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
           _POSIX_C_SOURCE >= 200112L;
           or cc -std=c99

DESCRIPTION
       The  modf()  function  breaks  the argument x into an integral part and a fractional part,
       each of which has the same sign as x.  The integral part is stored in the location pointed
       to by iptr.

RETURN VALUE
       The modf() function returns the fractional part of x.

       If x is a NaN, a NaN is returned, and *iptr is set to a NaN.

       If  x  is  positive infinity (negative infinity), +0 (-0) is returned, and *iptr is set to
       positive infinity (negative infinity).

ERRORS
       No errors occur.

ATTRIBUTES
   Multithreading (see pthreads(7))
       The modf(), modff(), and modfl() functions are thread-safe.

CONFORMING TO
       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO
       frexp(3), ldexp(3)

COLOPHON
       This page is part of release 3.53 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/.



                                            2013-06-21                                    MODF(3)