FLOOR(3M)FLOOR(3M)NAME
fabs, floor, ceil- absolute value, floor, and ceiling functions
SYNOPSIS
#include <math.h>
double floor(double x);
double ceil(double x);
double fabs(double x);
(ALSO AVAILABLE IN BSD)
double rint(double x);
DESCRIPTION
Fabs returns the absolute value |x|.
Floor returns the largest integer no greater than x.
Ceil returns the smallest integer no less than x.
Rint returns the integer (represented as a double precision number)
nearest x in the direction of the prevailing rounding mode.
NOTES
In the default rounding mode, to nearest, on a machine that conforms to
IEEE 754, rint(x) is the integer nearest x with the additional
stipulation that if |rint(x)-x|=1/2 then rint(x) is even. Other
rounding modes can make rint act like floor, or like ceil, or round
towards zero.
Another way to obtain an integer near x is to declare (in C):
double x; int k; k = x;
Most C compilers round x towards 0 to get the integer k, but some do
otherwise. If in doubt, use floor, ceil, or rint first, whichever you
intend. Also note that, if x is larger than k can accommodate, the
value of k and the presence or absence of an integer overflow are hard
to predict.
SEE ALSOabs(3), ieee(3M), math(3M)4th Berkeley Distribution August 1, 1992 FLOOR(3M)
