frexpf

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
       These  functions are used to split the number x into a normalized frac-
       tion and an exponent which is stored in exp.

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

       +----------------------------+---------------+---------+
       |Interface                   | Attribute     | Value   |
       +----------------------------+---------------+---------+
       |frexp(), frexpf(), frexpl() | Thread safety | MT-Safe |
       +----------------------------+---------------+---------+
CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

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

EXAMPLE
       The program below produces results such as the following:

       int
       main(int argc, char *argv[])
       {
           double x, r;
           int exp;

           x = strtod(argv[1], 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
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       latest    version    of    this    page,    can     be     found     at
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                                  2015-04-19                          FREXP(3)
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