# frexpl

```       integral components

SYNOPSIS
#include <math.h>

double frexp(double x, int *exp);
float frexpf(float x, int *exp);
long double frexpl(long double x, int *exp);

Link with -lm.

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

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

DESCRIPTION
The  frexp()  function  is used to split the number x into a normalized
fraction and an exponent which is stored in exp.

RETURN VALUE
The frexp() function returns the normalized fraction.  If the  argument
x  is  not zero, the normalized fraction is x times a power of two, and
its absolute value is always in the range 1/2 (inclusive) to 1  (exclu-
sive), that is, [0.5,1).

If  x  is zero, then the normalized fraction is zero and zero is stored
in exp.

If x is a NaN, a NaN is returned, and the value of *exp is unspecified.

If x is positive infinity (negative infinity), positive infinity (nega-
tive infinity) is returned, and the value of *exp is unspecified.

ERRORS
No errors occur.

ATTRIBUTES
Multithreading (see pthreads(7))
The frexp(), frexpf(), and frexpl() functions are thread-safe.

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

EXAMPLE
The program below produces results such as the following:

\$ ./a.out 2560
frexp(2560, &e) = 0.625: 0.625 * 2^12 = 2560
\$ ./a.out -4
frexp(-4, &e) = -0.5: -0.5 * 2^3 = -4
int exp;

x = strtod(argv, NULL);
r = frexp(x, &exp);

printf("frexp(%g, &e) = %g: %g * %d^%d = %g\n",
x, r, r, FLT_RADIX, exp, x);
exit(EXIT_SUCCESS);
}

SEE ALSO
ldexp(3), modf(3)

COLOPHON
This page is part of release 3.54 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/.

2013-08-06                          FREXP(3)```