MODF

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
ATTRIBUTES
CONFORMING TO
SEE ALSO
COLOPHON

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

For an explanation of the terms used in this section, see attributes(7).

Image grohtml-311361.png

CONFORMING TO

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

SEE ALSO

frexp(3), ldexp(3)

COLOPHON

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