SCALB
Section: Linux Programmer's Manual (3)
Updated: 20170915
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NAME
scalb, scalbf, scalbl  multiply floatingpoint number
by integral power of radix (OBSOLETE)
SYNOPSIS
#include <math.h>
double scalb(double x, double exp);
float scalbf(float x, float exp);
long double scalbl(long double x, long double exp);
Link with lm.
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
scalb():

_XOPEN_SOURCE >= 500
 /* Since glibc 2.19: */ _DEFAULT_SOURCE
 /* Glibc versions <= 2.19: */ _BSD_SOURCE  _SVID_SOURCE
scalbf(),
scalbl():

_XOPEN_SOURCE >= 600
 /* 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
or
exp
is a NaN, a NaN is returned.
If
x
is positive infinity (negative infinity),
and
exp
is not negative infinity,
positive infinity (negative infinity) is returned.
If
x
is +0 (0), and
exp
is not positive infinity, +0 (0) is returned.
If
x
is zero, and
exp
is positive infinity,
a domain error occurs, and
a NaN is returned.
If
x
is an infinity,
and
exp
is negative infinity,
a domain error occurs, and
a NaN 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:
 Domain error: x is 0, and exp is positive infinity, or x is positive infinity and exp is negative infinity and the other argument is not a NaN

An invalid floatingpoint exception
(FE_INVALID)
is raised.
 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.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
Interface  Attribute  Value

scalb(),
scalbf(),
scalbl()
 Thread safety  MTSafe

CONFORMING TO
scalb()
is specified in POSIX.12001, but marked obsolescent.
POSIX.12008 removes the specification of
scalb(),
recommending the use of
scalbln(3),
scalblnf(3),
or
scalblnl(3)
instead.
The
scalb()
function is from 4.3BSD.
scalbf()
and
scalbl()
are unstandardized;
scalbf()
is nevertheless present on several other systems
SEE ALSO
ldexp(3),
scalbln(3)
COLOPHON
This page is part of release 4.13 of the Linux
manpages
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/manpages/.
Index
 NAME

 SYNOPSIS

 DESCRIPTION

 RETURN VALUE

 ERRORS

 ATTRIBUTES

 CONFORMING TO

 SEE ALSO

 COLOPHON
