randbit

Calc Software Package for Number Calc

NAME
    randbit - additive 55 shuffle pseudo-random number generator

SYNOPSIS
    randbit([x])

TYPES
    x		integer

    return	integer

DESCRIPTION
    If x > 0, randbit(x) returns a pseudo-random integer in [0, 2^x),
    i.e. the same as rand(2^x).	 If the integer returned is

	    b_1 * 2^(x-1) + b_2 * 2^(x-2) + ... + b_n,

    where each b_i is 0 or 1, then b_1, b_2, ..., b_n may be
    considered as a sequence of x random bits.

    If x <= 0, randbit(x) causes the random-number generator to skip
    abs(x) bits, and returns abs(x).

    If x is omitted, it is assumed to have the value of 1.

    See the rand() help page for details on the additive 55 shuffle
    pseudo-random number generator.

EXAMPLE
    ; print srand(0), randbit(20), randbit(20), randbit(20), randbit(20)
    RAND state 817647 476130 944201 822573

    ; print srand(0), randbit(-20), randbit(20), randbit(-20), randbit(20)
    RAND state 20 476130 20 822573

LIMITS
    x != 0

LINK LIBRARY
    void zrand(long cnt, ZVALUE *res)

SEE ALSO
    seed, srand, randbit, isrand, random, srandom, israndom

## 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: 29.3 $
## @(#) $Id: randbit,v 29.3 2006/05/07 07:25:46 chongo Exp $
## @(#) $Source: /usr/local/src/cmd/calc/help/RCS/randbit,v $
##
## Under source code control:	1996/01/01 03:17:22
## File existed as early as:	1996
##
## chongo <was here> /\oo/\	http://www.isthe.com/chongo/
## Share and enjoy!  :-)	http://www.isthe.com/chongo/tech/comp/calc/