mirror of https://github.com/mkerrisk/man-pages
111 lines
3.1 KiB
Groff
111 lines
3.1 KiB
Groff
.\" Copyright 2001 Andries Brouwer <aeb@cwi.nl>.
|
|
.\"
|
|
.\" 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.\" manual page may be incorrect or out-of-date.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.
|
|
.\"
|
|
.TH RINT 3 2007-07-26 "" "Linux Programmer's Manual"
|
|
.SH NAME
|
|
nearbyint, nearbyintf, nearbyintl, rint, rintf, rintl \- round to nearest integer
|
|
.SH SYNOPSIS
|
|
.nf
|
|
.B #include <math.h>
|
|
.sp
|
|
.BI "double nearbyint(double " x );
|
|
.br
|
|
.BI "float nearbyintf(float " x );
|
|
.br
|
|
.BI "long double nearbyintl(long double " x );
|
|
.sp
|
|
.BI "double rint(double " x );
|
|
.br
|
|
.BI "float rintf(float " x );
|
|
.br
|
|
.BI "long double rintl(long double " x );
|
|
.fi
|
|
.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 nearbyint (),
|
|
.BR nearbyintf (),
|
|
.BR nearbyintl ():
|
|
_XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE; or
|
|
.I cc\ -std=c99
|
|
.br
|
|
.BR rint (),
|
|
.BR rintf (),
|
|
.BR rintl ():
|
|
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500 || _ISOC99_SOURCE; or
|
|
.I cc\ -std=c99
|
|
.ad b
|
|
.SH DESCRIPTION
|
|
The
|
|
.BR nearbyint ()
|
|
functions round their argument to an integer value in floating point
|
|
format, using the current rounding direction and without raising the
|
|
.I inexact
|
|
exception.
|
|
.LP
|
|
The
|
|
.BR rint ()
|
|
functions do the same, but will raise the
|
|
.I inexact
|
|
exception when the result differs in value from the argument.
|
|
.SH "RETURN VALUE"
|
|
The rounded integer value.
|
|
If \fIx\fP is integral or infinite,
|
|
\fIx\fP itself is returned.
|
|
.SH ERRORS
|
|
No errors other than
|
|
.B EDOM
|
|
and
|
|
.B ERANGE
|
|
can occur.
|
|
If \fIx\fP is NaN, then NaN is returned and
|
|
.I errno
|
|
may be set to
|
|
.BR EDOM .
|
|
.SH "CONFORMING TO"
|
|
C99.
|
|
.SH NOTES
|
|
SUSv2 and POSIX.1-2001 contain text about overflow (which might set
|
|
.I errno
|
|
to
|
|
.BR ERANGE ,
|
|
or raise an exception).
|
|
In practice, the result cannot overflow on any current machine,
|
|
so this error-handling stuff is just nonsense.
|
|
(More precisely, overflow can happen only when the maximum value
|
|
of the exponent is smaller than the number of mantissa bits.
|
|
For the IEEE-754 standard 32-bit and 64-bit floating point numbers
|
|
the maximum value of the exponent is 128 (resp. 1024), and the number
|
|
of mantissa bits is 24 (resp. 53).)
|
|
.SH "SEE ALSO"
|
|
.BR ceil (3),
|
|
.BR floor (3),
|
|
.BR lrint (3),
|
|
.BR round (3),
|
|
.BR trunc (3)
|