rint

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



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

SYNOPSIS
       #include <math.h>

       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);

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.

NOTES
       SUSv2  and  POSIX  1003.1-2001 contain text about overflow (which might
       set 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 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 (resp. 1024), and the number of
       mantissa bits is 24 (resp. 53).)

CONFORMING TO
       The rint() function conforms to BSD 4.3.  The other functions are  from
       C99.

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



                                  2001-05-31                           RINT(3)