Category : OS/2 Files
Archive   : GPPDEV8F.ZIP
Filename : ACG.H

// This may look like C code, but it is really -*- C++ -*-
/*
Copyright (C) 1988 Free Software Foundation
written by Dirk Grunwald ([email protected])

This file is part of the GNU C++ Library. This library is free
software; you can redistribute it and/or modify it under the terms of
the GNU Library General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version. This library 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 Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef _ACG_h
#define _ACG_h 1

#include
#include
#ifdef __GNUG__
#pragma interface
#endif

//
// Additive number generator. This method is presented in Volume II
// of The Art of Computer Programming by Knuth. I've coded the algorithm
// and have added the extensions by Andres Nowatzyk of CMU to randomize
// the result of algorithm M a bit by using an LCG & a spatial
// permutation table.
//
// The version presented uses the same constants for the LCG that Andres
// uses (chosen by trial & error). The spatial permutation table is
// the same size (it's based on word size). This is for 32-bit words.
//
// The ``auxillary table'' used by the LCG table varies in size, and
// is chosen to be the the smallest power of two which is larger than
// twice the size of the state table.
//

class ACG : public RNG {

unsigned long initialSeed; // used to reset generator
int initialTableEntry;

unsigned long *state;
unsigned long *auxState;
short stateSize;
short auxSize;
unsigned long lcgRecurr;
short j;
short k;

protected:

public:
ACG(unsigned long seed = 0, int size = 55);
virtual ~ACG();
//
// Return a long-words word of random bits
//
virtual unsigned long asLong();
virtual void reset();
};

#endif