huschi.net

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)