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.

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 3.38 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/.