Manual page for FLOOR(3M)
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 ALSO
abs(3),
ieee(3M),
math(3M)
Created by unroff & hp-tools.
© somebody (See intro for details). All Rights Reserved.
Last modified 11/5/97
