| .\" Copyright 2001 Andries Brouwer <aeb@cwi.nl>. |
| .\" |
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| .TH RINT 3 2001-05-31 "" "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 \-lm. |
| .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 EDOM and ERANGE can occur. |
| If \fIx\fP is NaN, then NaN is returned and |
| .I errno |
| may be set to EDOM. |
| .SH NOTES |
| SUSv2 and POSIX 1003.1-2001 contain text about overflow (which might set |
| .I errno |
| to 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 "CONFORMING TO" |
| The |
| .BR rint () |
| function conforms to 4.3BSD. |
| The other functions are from C99. |
| .SH "SEE ALSO" |
| .BR ceil (3), |
| .BR floor (3), |
| .BR lrint (3), |
| .BR nearbyint (3), |
| .BR round (3), |
| .BR trunc (3) |