scalb

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

NAME
       scalb,  scalbf,  scalbl  -  multiply  floating-point number by integral
       power of radix (OBSOLETE)

SYNOPSIS
       #include <math.h>

       double scalb(double x, double exp);
       float scalbf(float x, float exp);
       long double scalbl(long double x, long double exp);

       Link with -lm.

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

       scalb():
           _XOPEN_SOURCE >= 500
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
       scalbf(), scalbl():
           _XOPEN_SOURCE >= 600
               || /* 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 or exp is a NaN, a NaN is returned.

       If  x is positive infinity (negative infinity), and exp is not negative
       infinity, positive infinity (negative infinity) is returned.

       If x is +0 (-0), and exp is not positive infinity, +0 (-0) is returned.

       If x is zero, and exp is positive infinity, a domain error occurs,  and
       a NaN is returned.

       If  x  is an infinity, and exp is negative infinity, a domain error oc-
       curs, and a NaN 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  re-
       turn 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:

       Domain error: x is 0, and exp is positive infinity, or  x  is  positive
       infinity  and  exp is negative infinity and the other argument is not a
       NaN
              An invalid floating-point exception (FE_INVALID) is raised.

       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.

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

       +-----------------------------+---------------+---------+
       |Interface                    | Attribute     | Value   |
       +-----------------------------+---------------+---------+
       |scalb(), scalbf(), scalbl()  | Thread safety | MT-Safe |
       +-----------------------------+---------------+---------+
CONFORMING TO
       scalb()   is   specified   in  POSIX.1-2001,  but  marked  obsolescent.
       POSIX.1-2008 removes the specification of scalb(), recommending the use
       of  scalbln(3), scalblnf(3), or scalblnl(3) instead.  The scalb() func-
       tion is from 4.3BSD.

       scalbf() and scalbl()  are  unstandardized;  scalbf()  is  nevertheless
       present on several other systems

SEE ALSO
       ldexp(3), scalbln(3)

COLOPHON
       This  page  is  part of release 5.05 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                          SCALB(3)