PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT 

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

PROLOG         top

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

NAME         top

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

SYNOPSIS         top

       #include <math.h>
       double frexp(double num, int *exp);
       float frexpf(float num, int *exp);
       long double frexpl(long double num, int *exp);

DESCRIPTION         top

       The functionality described on this reference page is aligned with
       the ISO C standard. Any conflict between the requirements described
       here and the ISO C standard is unintentional. This volume of
       POSIX.1‐2008 defers to the ISO C standard.
       These functions shall break a floating-point number num into a
       normalized fraction and an integral power of 2. The integer exponent
       shall be stored in the int object pointed to by exp.

RETURN VALUE         top

       For finite arguments, these functions shall return the value x, such
       that x has a magnitude in the interval [½,1) 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         top

       No errors are defined.
       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       isnan(3p), ldexp(3p), modf(3p)
       The Base Definitions volume of POSIX.1‐2008, math.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/online.html .
       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                 2013                           FREXP(3P)

Pages that refer to this page: math.h(0p),  ldexp(3p),  modf(3p)