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():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       These functions break the argument x into an integral part and a  frac-
       tional  part,  each of which has the same sign as x.  The integral part
       is stored in the location pointed to by iptr.

RETURN VALUE
       These functions return 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
       For   an   explanation   of   the  terms  used  in  this  section,  see
       attributes(7).

       allbox; lbw24 lb  lb  l  l  l.   Interface Attribute Value  T{  modf(),
       modff(), modfl() T}   Thread safety  MT-Safe

CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO
       frexp(3), ldexp(3)

COLOPHON
       This  page  is  part of release 4.16 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest     version     of     this    page,    can    be    found    at
       https://www.kernel.org/doc/man-pages/.



                                  2017-09-15                           MODF(3)