/*
* RandomRBFGeneratorDrift.java
* Copyright (C) 2008 University of Waikato, Hamilton, New Zealand
* @author Albert Bifet
*
* 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.
*/
package tr.gov.ulakbim.jDenetX.streams.generators;
import tr.gov.ulakbim.jDenetX.options.FloatOption;
import tr.gov.ulakbim.jDenetX.options.IntOption;
import weka.core.Instance;
import java.util.Random;
public class RandomRBFGeneratorDrift extends RandomRBFGenerator {
@Override
public String getPurposeString() {
return "Generates a random radial basis function stream.";
}
private static final long serialVersionUID = 1L;
public FloatOption speedChangeOption = new FloatOption("speedChange", 's',
"Speed of change of centroids in the model.", 0, 0, Float.MAX_VALUE);
public IntOption numDriftCentroidsOption = new IntOption("numDriftCentroids", 'k',
"The number of centroids with drift.", 50, 0, Integer.MAX_VALUE);
protected double[][] speedCentroids;
@Override
public Instance nextInstance() {
//Update Centroids with drift
int len = this.numDriftCentroidsOption.getValue();
if (len > this.centroids.length) {
len = this.centroids.length;
}
for (int j = 0; j < len; j++) {
for (int i = 0; i < this.numAttsOption.getValue(); i++) {
this.centroids[j].centre[i] += this.speedCentroids[j][i] * this.speedChangeOption.getValue();
if (this.centroids[j].centre[i] > 1) {
this.centroids[j].centre[i] = 1;
this.speedCentroids[j][i] = -this.speedCentroids[j][i];
}
if (this.centroids[j].centre[i] < 0) {
this.centroids[j].centre[i] = 0;
this.speedCentroids[j][i] = -this.speedCentroids[j][i];
}
}
}
return super.nextInstance();
}
@Override
protected void generateCentroids() {
super.generateCentroids();
Random modelRand = new Random(this.modelRandomSeedOption.getValue());
int len = this.numDriftCentroidsOption.getValue();
if (len > this.centroids.length) {
len = this.centroids.length;
}
this.speedCentroids = new double[len][this.numAttsOption.getValue()];
for (int i = 0; i < len; i++) {
double[] randSpeed = new double[this.numAttsOption.getValue()];
double normSpeed = 0.0;
for (int j = 0; j < randSpeed.length; j++) {
randSpeed[j] = modelRand.nextDouble();
normSpeed += randSpeed[j] * randSpeed[j];
}
normSpeed = Math.sqrt(normSpeed);
for (int j = 0; j < randSpeed.length; j++) {
randSpeed[j] /= normSpeed;
}
this.speedCentroids[i] = randSpeed;
}
}
@Override
public void getDescription(StringBuilder sb, int indent) {
// TODO Auto-generated method stub
}
}