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 || _POSIX_C_SOURCE >= 200112L;
              or cc -std=c99
       scalbn(), scalbnf(), scalbnl():
              _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
              _POSIX_C_SOURCE >= 200112L;
              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.

ATTRIBUTES
   Multithreading (see pthreads(7))
       The scalbn(), scalbnf(), scalbnl(), scalbln(), scalblnf(), and  scalblnl()  functions  are
       thread-safe.

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 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 3.74 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 http://www.kernel.org/doc/man-pages/.



                                            2013-06-21                                 SCALBLN(3)