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



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(): _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99
       scalbn(), scalbnf(), scalbnl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99

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.

CONFORMING TO
       C99, POSIX.1-2001.

NOTES
       These functions differ from the obsolete functions described in scalb(3) in the type of their second argument.  The func-
       tions  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 3.25 of the Linux man-pages project.  A description of the project,  and  information  about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



                                                           2008-08-11                                                 SCALBLN(3)