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RINT(3)                    Linux Programmer's Manual                   RINT(3)



NAME
       nearbyint,  nearbyintf, nearbyintl, rint, rintf, rintl - round to near-
       est integer

SYNOPSIS
       #include <&lt;math.h>&gt;

       double nearbyint(double x);
       float nearbyintf(float x);
       long double nearbyintl(long double x);

       double rint(double x);
       float rintf(float x);
       long double rintl(long double x);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       nearbyint(), nearbyintf(), nearbyintl(): _XOPEN_SOURCE >= 600 ||
       _ISOC99_SOURCE; or cc -std=c99
       rint(), rintf(), rintl(): _BSD_SOURCE || _SVID_SOURCE ||
       _XOPEN_SOURCE >= 500 || _ISOC99_SOURCE; or cc -std=c99

DESCRIPTION
       The nearbyint() functions round their argument to an integer  value  in
       floating point format, using the current rounding direction and without
       raising the inexact exception.

       The rint() functions do the same, but will raise the inexact  exception
       when the result differs in value from the argument.

RETURN VALUE
       The  rounded  integer value.  If x is integral or infinite, x itself is
       returned.

ERRORS
       No errors other than EDOM and ERANGE can occur.  If x is NaN, then  NaN
       is returned and errno may be set to EDOM.

CONFORMING TO
       C99.

NOTES
       SUSv2  and  POSIX.1-2001  contain  text about overflow (which might set
       errno to ERANGE, or raise an exception).  In practice, the result  can-
       not  overflow  on  any current machine, so this error-handling stuff is
       just nonsense.  (More precisely, overflow can happen only when the max-
       imum 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 (respectively, 1024), and the num-
       ber of mantissa bits is 24 (respectively, 53).)

SEE ALSO
       ceil(3), floor(3), lrint(3), round(3), trunc(3)

COLOPHON
       This page is part of release 3.05 of the Linux  man-pages  project.   A
       description  of  the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



                                  2007-07-26                           RINT(3)