FREXP(3P)                                           POSIX Programmer's Manual                                          FREXP(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       frexp, frexpf, frexpl - extract mantissa and exponent from a double precision number

SYNOPSIS
       #include <math.h>

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


DESCRIPTION
       These  functions shall break a floating-point number num into a normalized fraction and an integral power of 2. The inte-
       ger exponent shall be stored in the int object pointed to by exp.

RETURN VALUE
       For finite arguments, these functions shall return the value x, such that x has a magnitude in the interval [0.5,1) or 0,
       and num equals x times 2 raised to the power *exp.

       If num is NaN, a NaN shall be returned, and the value of *exp is unspecified.

       If num is +-0, +-0 shall be returned, and the value of *exp shall be 0.

       If num is +-Inf, num shall be returned, and the value of *exp is unspecified.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       isnan(), ldexp(), modf(), the Base Definitions volume of IEEE Std 1003.1-2001, <math.h>

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open  Group
       Standard   is   the   referee   document.   The   original   Standard   can   be   obtained  online  at  http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                     FREXP(3P)