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



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


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

SSYYNNOOPPSSIISS
       #include <math.h>

       double frexp(double _n_u_m, int *_e_x_p);
       float frexpf(float _n_u_m, int *_e_x_p);
       long double frexpl(long double _n_u_m, int *_e_x_p);

DDEESSCCRRIIPPTTIIOONN
       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 _n_u_m into a
       normalized fraction and an integral power of 2. The integer exponent
       shall be stored in the iinntt object pointed to by _e_x_p.

RREETTUURRNN VVAALLUUEE
       For finite arguments, these functions shall return the value _x, such
       that _x has a magnitude in the interval [1/2,1) or 0, and _n_u_m equals _x
       times 2 raised to the power *_e_x_p.

       If _n_u_m is NaN, a NaN shall be returned, and the value of *_e_x_p is
       unspecified.

       If _n_u_m is +-0, +-0 shall be returned, and the value of *_e_x_p shall be 0.

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

EERRRROORRSS
       No errors are defined.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       None.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _i_s_n_a_n(), _l_d_e_x_p(), _m_o_d_f()

       The Base Definitions volume of POSIX.1-2008, <<mmaatthh..hh>>

CCOOPPYYRRIIGGHHTT
       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(3)
