issq

来自「Calc Software Package for Number Calc」· 代码 · 共 73 行

NAME
    issq - whether a value is a square

SYNOPSIS
    issq(x)

TYPES
    x		real

    return	int

DESCRIPTION
    Determine if x is a square.	 If there exists integers a, b such that:

	x == a^2 / b^2		(b != 0)

    return 1, otherwise return 0.

    Note that issq() works on rational values, so:

    	issq(25/16) == 1

    If you want to test for prefect square integers, you need to exclude
    non-integer values before you test:

    	isint(curds) && issq(curds)

EXAMPLE
    ; print issq(25), issq(3), issq(0)
    1 0 1

    ; print issq(4/25), issq(-4/25), issq(pi())
    1 0 0

LIMITS
    none

LINK LIBRARY
    BOOL qissquare(NUMBER *x)
    BOOL zissquare(ZVALUE x)

SEE ALSO
    isassoc, isatty, isblk, isconfig, isdefined, iserror, iseven, isfile,
    ishash, isident, isint, islist, ismat, ismult, isnull, isnum, isobj,
    isobjtype, isodd, isprime, isrand, israndom, isreal, isrel,
    issimple, isstr, istype

## Copyright (C) 1999  Landon Curt Noll
##
## Calc is open software; you can redistribute it and/or modify it under
## the terms of the version 2.1 of the GNU Lesser General Public License
## as published by the Free Software Foundation.
##
## Calc is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
## or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU Lesser General
## Public License for more details.
##
## A copy of version 2.1 of the GNU Lesser General Public License is
## distributed with calc under the filename COPYING-LGPL.  You should have
## received a copy with calc; if not, write to Free Software Foundation, Inc.
## 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
##
## @(#) $Revision: 29.4 $
## @(#) $Id: issq,v 29.4 2006/06/04 21:12:23 chongo Exp $
## @(#) $Source: /usr/local/src/cmd/calc/help/RCS/issq,v $
##
## Under source code control:	1994/10/21 02:21:31
## File existed as early as:	1994
##
## chongo <was here> /\oo/\	http://www.isthe.com/chongo/
## Share and enjoy!  :-)	http://www.isthe.com/chongo/tech/comp/calc/