Name
scalb, scalbf, scalbl — multiply floating-point 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); |
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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:
xis 0, andexpis positive infinity, orxis positive infinity andexpis negative infinity and the other argument is not a NaN -
An invalid floating-point exception (
FE_INVALID) is raised. - 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.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
scalb(), scalbf(), scalbl() |
Thread safety | MT-Safe |
CONFORMING TO
scalb() is specified in
POSIX.1-2001, but marked obsolescent. POSIX.1-2008 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
COLOPHON
This page is part of release 4.07 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/.
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Copyright 2004 Andries Brouwer <aebcwi.nl>. and Copyright 2008, Linux Foundation, written by Michael Kerrisk <mtk.manpagesgmail.com> %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END |