floor.3m

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3M 代码 · 共 76 行

.\" SCCSID: @(#)floor.3m	8.1	9/11/90
.TH floor 3m VAX
.SH Name
fabs, floor, ceil, fmod, rint \- absolute value, floor, ceiling, 
floating point remainder, and round-to-nearest functions 
.SH Syntax 
.nf
.B #include <math.h>
.PP
.B double floor(\fIx\fP)
.B double \fIx\fP;
.PP
.B double ceil(\fIx\fP)
.B double \fIx\fP;
.PP
.B double fabs(\fIx\fP)
.B double \fIx\fP;
.PP
.B double fmod (\fIx, y\fP)
.B double \fIx, y\fP;
.PP
.B double rint(\fIx\fP)
.B double \fIx\fP;
.fi
.SH Description
.NXR "fabs subroutine"
.NXR "floor subroutine"
.NXR "ceil subroutine"
.NXR "rint subroutine"
.NXR "floor function" "returning integer"
.NXR "ceiling function" "returning integer"
.NXR "absolute value function"
.NXR "floating point remainder"
.NXR "round-to-nearest function"
The
.PN fabs 
routine returns the absolute value |\|x\||.
.PP
The
.PN floor 
routine returns the largest integer no greater than x.
.PP
The
.PN ceil
routine returns the smallest integer no less than x.
.PP
The
.PN fmod
routine returns the floating point remainder of the division of
.I x\^
by
.IR y :
zero if
.I y\^
is zero or if
.I x/y\^
would overflow;
otherwise the number
.I f\^
with the same sign as
.IR x ,
such that
.I "x = iy + f"
for some integer
.IR i ,
and
.RI | \|f "| < |" \|y |\|.
.PP
The
.PN rint 
routine
returns the integer (represented as a double precision number)
nearest x in the direction of the prevailing rounding mode.
.SH See Also
abs(3), intro(3m)