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

NAME         top

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

SYNOPSIS         top

       #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 ||

DESCRIPTION         top

       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         top

       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         top

       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

       These functions do not set errno.

VERSIONS         top

       These functions first appeared in glibc in version 2.1.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface                         Attribute     Value   │
       │scalbn(), scalbnf(), scalbnl(),   │ Thread safety │ MT-Safe │
       │scalbln(), scalblnf(), scalblnl() │               │         │

CONFORMING TO         top

       C99, POSIX.1-2001, POSIX.1-2008.

NOTES         top

       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         top

       ldexp(3), scalb(3)

COLOPHON         top

       This page is part of release 4.08 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

                                 2016-03-15                       SCALBLN(3)