round

ROUND(3)		  Linux Programmer’s Manual		     ROUND(3)



NAME
       round, roundf, roundl - round to nearest integer, away from zero

SYNOPSIS
       #include <math.h>

       double round(double x);
       float roundf(float x);
       long double roundl(long double x);

DESCRIPTION
       These  functions	 round	x  to  the nearest integer, but round halfway
       cases away from zero (regardless of the current	rounding  direction),
       instead of to the nearest even integer like rint().

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
       POSIX  1003.1-2001 contains 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  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).)

CONFORMING TO
       C99.

SEE ALSO
       ceil(3), floor(3), lround(3), nearbyint(3), rint(3), trunc(3)



				  2001-05-31			     ROUND(3)