
SCALBLN(3) Linux Programmer's Manual SCALBLN(3)
NAME
scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl  multiply floatingpoint 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 floatingpoint exception (FE_OVERFLOW) is raised.
Range error, underflow
An underflow floatingpoint 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
threadsafe.
CONFORMING TO
C99, POSIX.12001.
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 3.55 of the Linux manpages project. A description of the
project, and information about reporting bugs, can be found at
http://www.kernel.org/doc/manpages/.
20130621 SCALBLN(3) 
