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():
          _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 4.09 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/.

                              2016-03-15                        SCALBLN(3)

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