scalbn

SCALBLN(3)                 Linux Programmer's Manual                SCALBLN(3)

NAME
       scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply float-
       ing-point number by integral power of radix

SYNOPSIS
       #include <math.h>

       double scalbln(double x, long int exp);
       float scalblnf(float x, long int exp);
       long double scalblnl(long double x, long int exp);

       double scalbn(double x, int exp);
       float scalbnf(float x, int exp);
       long double scalbnl(long double x, int exp);

       Link with -lm.

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

       scalbln(), scalblnf(), scalblnl():
              _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
                  || /* Since glibc 2.19: */ _DEFAULT_SOURCE
       scalbn(), scalbnf(), scalbnl():
              _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
                  || /* Since glibc 2.19: */ _DEFAULT_SOURCE
                  || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       These functions multiply their first argument x by FLT_RADIX  (probably
       2) to the power of exp, that is:

           x * FLT_RADIX ** exp

       The definition of FLT_RADIX can be obtained by including <float.h>.

RETURN VALUE
       On success, these functions return x * FLT_RADIX ** exp.

       If x is a NaN, a NaN is returned.

       If x is positive infinity (negative infinity), positive infinity (nega-
       tive infinity) is returned.

       If x is +0 (-0), +0 (-0) is returned.

       If the result overflows, a range error occurs, and the functions return
       HUGE_VAL,  HUGE_VALF,  or HUGE_VALL, respectively, with a sign the same
       as x.

       If the result underflows, a  range  error  occurs,  and  the  functions
       return zero, with a sign the same as x.

ERRORS
       See  math_error(7) for information on how to determine whether an error
       has occurred when calling these functions.

       The following errors can occur:

       Range error, overflow
              An overflow floating-point exception (FE_OVERFLOW) is raised.

       Range error, underflow
              An underflow floating-point exception (FE_UNDERFLOW) is raised.

       These functions do not set errno.

VERSIONS
       These functions first appeared in glibc in version 2.1.

ATTRIBUTES
       For  an  explanation  of  the  terms  used   in   this   section,   see
       attributes(7).

       +----------------------------------+---------------+---------+
       |Interface                         | Attribute     | Value   |
       +----------------------------------+---------------+---------+
       |scalbn(), scalbnf(), scalbnl(),   | Thread safety | MT-Safe |
       |scalbln(), scalblnf(), scalblnl() |               |         |
       +----------------------------------+---------------+---------+
CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

NOTES
       These  functions  differ  from  the  obsolete  functions  described  in
       scalb(3) in the type of their second argument.  The functions described
       on this page have a second argument of an integral type, while those in
       scalb(3) have a second argument of type double.

       If FLT_RADIX equals 2 (which is usual), then scalbn() is equivalent  to
       ldexp(3).

SEE ALSO
       ldexp(3), scalb(3)

COLOPHON
       This  page  is  part of release 4.15 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest     version     of     this    page,    can    be    found    at
       https://www.kernel.org/doc/man-pages/.

                                  2017-09-15                        SCALBLN(3)
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