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





NAME
       nearbyint,  nearbyintf, nearbyintl, rint, rintf, rintl -
       round to nearest 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 inte-
       ger  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 inex-
       act 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 excep-
       tion).  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  num-
       ber 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)
