source: main/branches/64_bit_Greenstone/greenstone2/common-src/indexers/mg/lib/random.h@ 24031

/**************************************************************************
 *
 * random.h -- pseudo random number generator
 * Copyright (C) 1994  Chris Wallace ([email protected])
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 **************************************************************************/

#ifndef RANDOM_H
#define RANDOM_H

/*
 *  A random number generator called as a function by
 *  random (iseed)  or  irandm (iseed)
 *  The parameter should be a pointer to a 2-element long vector.
 *  The first function returns a double uniform in 0 .. 1.
 *  The second returns a long integer uniform in 0 .. 2**31-1
 *  Both update iseed[] in exactly the same way.
 *  iseed[] must be a 2-element integer vector.
 *  The initial value of the second element may be anything.
 *
 *  The period of the random sequence is 2**32 * (2**32-1)
 *  The table mt[0:127] is defined by mt[i] = 69069 ** (128-i)
 */
#include "mglong.h"

double random (mg_s_long is [2]);
mg_s_long irandm (mg_s_long is [2]);

#endif