syntheticdata2.cpp

Scalable k-means software and test datasets This package (a Unix tar file, gzipped) contains the sou

/* 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.

*/

/* syntheticdata.cpp */

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "singleton.h"
#include "subcluster.h"
#include "database.h"
#include "syntheticdata.h"

SyntheticData::SyntheticData(int models, int dim, int points)
	 : models(models), dimensions(dim), numPoints(points)
{
	data = new float[points * dim];
}

SyntheticData::~SyntheticData(void)
{
	delete []data;
}

// Initialize the data points.
void SyntheticData::initData(float meanRange, float stdDevRange)
{
	int i,j,k;
	int model;
	float x1, x2, z1, z2;

	srand(10);

	float mean[models][dimensions];
	float stdDev[models][dimensions];

	// Initialize mean and standard deviation for each model.
	for (i = 0; i < models; i++) {
		for (j = 0; j < dimensions; j++) {
			mean[i][j] = (float) (drand48() * meanRange);
			stdDev[i][j] = (float) (drand48() * stdDevRange);
//        		printf("Model (%d,%d): %f, %f\n", i, j, mean[i][j], stdDev[i][j]);
		}
	}

	for(i = 0; i < numPoints; i++) {
                model = (int) (drand48() * models);
		for (j = 0; j < dimensions; j += 2) {
			x1 = (float) drand48();
			x2 = (float) drand48();
			z1 = (float) (sqrt(-2.0 * log (x1)) * cos(2.0 * M_PI * x2));
			z2 = (float) (sqrt(-2.0 * log (x1)) * sin(2.0 * M_PI * x2));
//			printf("%f %f %f %f\n", x1, x2, z1, z2);
			z1 = z1 * stdDev[model][j] + mean[model][j];
			z2 = z2 * stdDev[model][j + 1] + mean[model][j + 1];
			data[i * dimensions + j] = z1;
			if (j < dimensions - 1) {
				data[i * dimensions + j + 1] = z2;
			}
		}
	}
}

// Reset counter, i.e return first point next time getPoint is called.
void SyntheticData::reset(void)
{
	current = 0;
}

// Return a pointer to an array of floats containing the current point.
// The allocated memory may be read by the user but belongs to the
// Database class.
float *SyntheticData::getPoint(void)
{
	if (current < numPoints)
		return &data[current++ * dimensions];
	else
		return 0;
}

/* End of file syntheticdata.cpp */