random.cpp

来自「Scalable k-means software and test datas」· C++ 代码 · 共 110 行

/* Scalable K-means clustering software
Copyright (C) 2000  Fredrik Farnstrom and James Lewis

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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.


See the file README.TXT for more information.

*/

/* random.cpp */

#include <math.h>
#include "random.h"

#define RNDMASK 0x7fff

#define M1 259200
#define IA1 7141
#define IC1 54773
#define RM1 (1.0/M1)
#define M2 134456
#define IA2 8121
#define IC2 28411
#define RM2 (1.0/M2)
#define M3 243000
#define IA3 4561
#define IC3 51349

static unsigned long next_rand = 1;

extern "C" int time(int);

// Generate a pseudo random number in the range from 0.0 to 1.0.

REAL random(void)
{
  next_rand = next_rand * 1812433253L + 12345L;

  return ((int)(next_rand >> 16) & RNDMASK) * 2.0 / 65535;
}


// Set seed value for the pseudo random number generator.

void seed(int s)
{
  next_rand = (unsigned long int)s;
}

RandomGenerator::RandomGenerator(void)
{
	seed(time(0));
}

RandomGenerator::RandomGenerator(int initseed)
{
	seed(initseed);
}

void RandomGenerator::seed(int s)
{
	nextRand = s;
//	srand48(s);
}

REAL RandomGenerator::random(void)
{
  nextRand = nextRand*1812433253L + 12345L;
  return ((int)(nextRand >> 16) & RNDMASK) * 2.0/65535;
}

unsigned long RandomGenerator::randomInt(void)
{
	nextRand = nextRand*1812433253L + 12345L;
	return ((int)(nextRand >> 16) & RNDMASK);
//	return lrand48();
}

unsigned long RandomGenerator::randomInt(unsigned long range)
{
	nextRand = nextRand * 1812433253L + 12345L;
	return (unsigned long)((range*((int)(nextRand >> 16) & RNDMASK))/
			(RNDMASK+1.0));
//	return lrand48();
}

unsigned long RandomGenerator::maxRandomInt(void)
{
	return RNDMASK;
//	return 0x80000000;
}

RandomGenerator RandomGenerator::defaultRandomGenerator;


/* End of file random.cpp */