RINT(3M) RINT(3M)
NAME
aint, anint, ceil, floor, rint, irint, nint  round to integral value
in floatingpoint or integer format
SYNOPSIS
#include <<math.h>>
double aint(x)
double x;
double anint(x)
double x;
double ceil(x)
double x;
double floor(x)
double x;
double rint(x)
double x;
int irint(x)
double x;
int nint(x)
double x;
DESCRIPTION
aint(), anint(), ceil(), floor(), and rint() convert a double value
into an integral value in double format. They vary in how they choose
the result when the argument is not already an integral value. Here an
"integral value" means a value of a mathematical integer, which however
might be too large to fit in a particular computer's int format. All
sufficiently large values in a particular floatingpoint format are
already integral; in IEEE doubleprecision format, that means all val
ues >= 2**52. Zeros, infinities, and quiet NaNs are treated as inte
gral values by these functions, which always preserve their argument's
sign.
aint() returns the integral value between x and 0, nearest x. This
corresponds to IEEE rounding toward zero and to the Fortran generic
intrinsic function aint().
anint() returns the nearest integral value to x, except halfway cases
are rounded to the integral value larger in magnitude. This corre
sponds to the Fortran generic intrinsic function anint().
ceil() returns the least integral value greater than or equal to x.
This corresponds to IEEE rounding toward positive infinity.
floor() returns the greatest integral value less than or equal to x.
This corresponds to IEEE rounding toward negative infinity.
rint() rounds x to an integral value according to the current IEEE
rounding direction.
irint() converts x into int format according to the current IEEE round
ing direction.
nint() converts x into int format rounding to the nearest int value,
except halfway cases are rounded to the int value larger in magnitude.
This corresponds to the Fortran generic intrinsic function nint().
15 October 1987 RINT(3M)
