2008-08-01 05:37:29 +00:00
|
|
|
.\" Copyright 2004 Andries Brouwer <aeb@cwi.nl>.
|
|
|
|
.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
|
|
|
|
.\" <mtk.manpages@gmail.com>
|
|
|
|
.\"
|
|
|
|
.\" 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.\" manual page may be incorrect or out-of-date.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.
|
|
|
|
.\"
|
_exit.2, brk.2, capget.2, chdir.2, chmod.2, chown.2, chroot.2, getdtablesize.2, gethostname.2, getpagesize.2, getsid.2, killpg.2, mknod.2, mknodat.2, poll.2, posix_fadvise.2, pread.2, readlink.2, setpgid.2, setreuid.2, sigaltstack.2, stat.2, symlink.2, sync.2, truncate.2, vfork.2, wait.2, wait4.2, a64l.3, abs.3, acos.3, acosh.3, asin.3, asinh.3, atan.3, atan2.3, atoi.3, cbrt.3, ceil.3, copysign.3, cosh.3, dirfd.3, div.3, ecvt.3, erf.3, erfc.3, exp.3, exp2.3, fabs.3, fdim.3, ffs.3, floor.3, fma.3, fmax.3, fmin.3, fmod.3, fpclassify.3, frexp.3, ftw.3, fwide.3, gcvt.3, getcwd.3, getdate.3, getgrent.3, gethostid.3, getpass.3, getpwent.3, getsubopt.3, getw.3, hypot.3, ilogb.3, index.3, isalpha.3, isgreater.3, iswblank.3, j0.3, ldexp.3, lockf.3, log.3, log10.3, log1p.3, logb.3, lrint.3, lround.3, mkstemp.3, mktemp.3, modf.3, mq_receive.3, mq_send.3, nan.3, nextafter.3, posix_fallocate.3, posix_memalign.3, printf.3, qecvt.3, random.3, realpath.3, remainder.3, remquo.3, rint.3, round.3, scalb.3, scalbln.3, scanf.3, siginterrupt.3, signbit.3, sigset.3, sinh.3, sqrt.3, strcasecmp.3, strcat.3, strchr.3, strcmp.3, strcoll.3, strcpy.3, strfry.3, strpbrk.3, strsep.3, strspn.3, strstr.3, strtod.3, strtok.3, strtol.3, strtoul.3, strxfrm.3, tanh.3, tgamma.3, trunc.3, ttyslot.3, ualarm.3, usleep.3, wprintf.3, armscii-8.7, cp1251.7, iso_8859-10.7, iso_8859-11.7, iso_8859-13.7, iso_8859-14.7, iso_8859-3.7, iso_8859-5.7, iso_8859-6.7, iso_8859-8.7, koi8-u.7: tstamp
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2010-09-19 17:19:13 +00:00
|
|
|
.TH SCALBLN 3 2010-09-20 "" "Linux Programmer's Manual"
|
2008-08-01 05:37:29 +00:00
|
|
|
.SH NAME
|
|
|
|
scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl \-
|
|
|
|
multiply floating-point number by integral power of radix
|
|
|
|
.SH SYNOPSIS
|
|
|
|
.B #include <math.h>
|
|
|
|
.sp
|
|
|
|
.BI "double scalbln(double " x ", long int " exp );
|
|
|
|
.br
|
|
|
|
.BI "float scalblnf(float " x ", long int " exp );
|
|
|
|
.br
|
|
|
|
.BI "long double scalblnl(long double " x ", long int " exp );
|
|
|
|
.sp
|
|
|
|
.BI "double scalbn(double " x ", int " exp );
|
|
|
|
.br
|
|
|
|
.BI "float scalbnf(float " x ", int " exp );
|
|
|
|
.br
|
|
|
|
.BI "long double scalbnl(long double " x ", int " exp );
|
|
|
|
.sp
|
|
|
|
Link with \fI\-lm\fP.
|
|
|
|
.sp
|
|
|
|
.in -4n
|
|
|
|
Feature Test Macro Requirements for glibc (see
|
|
|
|
.BR feature_test_macros (7)):
|
|
|
|
.in
|
|
|
|
.sp
|
|
|
|
.ad l
|
|
|
|
.BR scalbln (),
|
|
|
|
.BR scalblnf (),
|
|
|
|
.BR scalblnl ():
|
2010-09-18 15:20:48 +00:00
|
|
|
.RS
|
|
|
|
_XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
|
|
|
|
_POSIX_C_SOURCE\ >=\ 200112L;
|
|
|
|
.br
|
|
|
|
or
|
2008-08-01 05:37:29 +00:00
|
|
|
.I cc\ -std=c99
|
2010-09-18 15:20:48 +00:00
|
|
|
.RE
|
2008-08-01 05:37:29 +00:00
|
|
|
.br
|
|
|
|
.BR scalbn (),
|
|
|
|
.BR scalbnf (),
|
|
|
|
.BR scalbnl ():
|
2010-09-18 15:20:48 +00:00
|
|
|
.RS
|
|
|
|
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
|
|
|
|
_POSIX_C_SOURCE\ >=\ 200112L;
|
|
|
|
.br
|
|
|
|
or
|
2008-08-01 05:37:29 +00:00
|
|
|
.I cc\ -std=c99
|
2010-09-18 15:20:48 +00:00
|
|
|
.RE
|
2008-08-01 05:37:29 +00:00
|
|
|
.ad b
|
|
|
|
.SH DESCRIPTION
|
|
|
|
These functions multiply their first argument
|
|
|
|
.I x
|
|
|
|
by
|
|
|
|
.B FLT_RADIX
|
|
|
|
(probably 2)
|
|
|
|
to the power of
|
|
|
|
.IR exp ,
|
|
|
|
that is:
|
|
|
|
.nf
|
|
|
|
|
|
|
|
x * FLT_RADIX ** exp
|
|
|
|
.fi
|
|
|
|
|
|
|
|
The definition of
|
|
|
|
.B FLT_RADIX
|
|
|
|
can be obtained by including
|
|
|
|
.IR <float.h> .
|
|
|
|
.\" not in /usr/include but in a gcc lib
|
|
|
|
.SH RETURN VALUE
|
|
|
|
On success, these functions return \fIx\fP * \fBFLT_RADIX\fP ** \fIexp\fP.
|
|
|
|
|
|
|
|
If
|
|
|
|
.I x
|
|
|
|
is a NaN, a NaN is returned.
|
|
|
|
|
|
|
|
If
|
|
|
|
.I x
|
|
|
|
is positive infinity (negative infinity),
|
|
|
|
positive infinity (negative infinity) is returned.
|
|
|
|
|
|
|
|
If
|
|
|
|
.I x
|
|
|
|
is +0 (\-0), +0 (\-0) is returned.
|
|
|
|
|
|
|
|
If the result overflows,
|
2008-08-04 16:00:58 +00:00
|
|
|
a range error occurs,
|
2008-08-01 05:37:29 +00:00
|
|
|
and the functions return
|
|
|
|
.BR HUGE_VAL ,
|
|
|
|
.BR HUGE_VALF ,
|
|
|
|
or
|
|
|
|
.BR HUGE_VALL ,
|
|
|
|
respectively, with a sign the same as
|
|
|
|
.IR x .
|
|
|
|
|
|
|
|
If the result underflows,
|
2008-08-04 16:00:58 +00:00
|
|
|
a range error occurs,
|
2008-08-01 05:37:29 +00:00
|
|
|
and the functions return zero, with a sign the same as
|
|
|
|
.IR x .
|
|
|
|
.SH ERRORS
|
|
|
|
See
|
|
|
|
.BR math_error (7)
|
|
|
|
for information on how to determine whether an error has occurred
|
|
|
|
when calling these functions.
|
|
|
|
.PP
|
|
|
|
The following errors can occur:
|
|
|
|
.TP
|
|
|
|
Range error, overflow
|
|
|
|
.\" .I errno
|
|
|
|
.\" is set to
|
|
|
|
.\" .BR ERANGE .
|
|
|
|
An overflow floating-point exception
|
|
|
|
.RB ( FE_OVERFLOW )
|
|
|
|
is raised.
|
|
|
|
.TP
|
|
|
|
Range error, underflow
|
|
|
|
.\" .I errno
|
|
|
|
.\" is set to
|
|
|
|
.\" .BR ERANGE .
|
|
|
|
An underflow floating-point exception
|
|
|
|
.RB ( FE_UNDERFLOW )
|
|
|
|
is raised.
|
|
|
|
.PP
|
|
|
|
These functions do not set
|
|
|
|
.IR errno .
|
|
|
|
.\" FIXME . Is it intentional that these functions do not set errno?
|
|
|
|
.\" Bug raised: http://sources.redhat.com/bugzilla/show_bug.cgi?id=6803
|
2008-08-11 17:13:47 +00:00
|
|
|
.SH VERSIONS
|
|
|
|
These functions first appeared in glibc in version 2.1.
|
2008-08-01 05:37:29 +00:00
|
|
|
.SH "CONFORMING TO"
|
|
|
|
C99, POSIX.1-2001.
|
|
|
|
.SH NOTES
|
|
|
|
These functions differ from the obsolete functions described in
|
|
|
|
.BR 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
|
|
|
|
.BR scalb (3)
|
|
|
|
have a second argument of type
|
|
|
|
.IR double .
|
|
|
|
|
|
|
|
If
|
|
|
|
.B FLT_RADIX
|
|
|
|
equals 2 (which is usual), then
|
|
|
|
.BR scalbn ()
|
|
|
|
is equivalent to
|
|
|
|
.BR ldexp (3).
|
|
|
|
.SH "SEE ALSO"
|
|
|
|
.BR ldexp (3),
|
|
|
|
.BR scalb (3)
|