SCALBLN
Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
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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(),
scalbln(),
scalblnf(),
scalblnl()
| Thread safety | MT-Safe
|
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 4.13 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/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- VERSIONS
-
- ATTRIBUTES
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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