NAME

       scalbn,  scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply floating-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 (negative 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)