/*
* RapidMiner
*
* Copyright (C) 2001-2008 by Rapid-I and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapid-i.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.operator.learner.functions.kernel.functions;
/**
* Returns the value of a Polynomial kernel of both examples.
*
* @author Ingo Mierswa
* @version $Id: PolynomialKernel.java,v 1.4 2008/09/12 10:29:42 tobiasmalbrecht Exp $
*/
public class PolynomialKernel extends Kernel {
private static final long serialVersionUID = 1296800822192183260L;
/** The parameter degree of the polynomial kernel. */
private double degree = 3;
/** The parameter shift of the polynomial kernel. */
private double shift = 1.0d;
public int getType() {
return KERNEL_POLYNOMIAL;
}
public double getDegree() {
return degree;
}
/** Sets the used polynomial parameters. */
public void setPolynomialParameters(double degree, double shift) {
this.degree = degree;
this.shift = shift;
}
/** Subclasses must implement this method. */
public double calculateDistance(double[] x1, double[] x2) {
double prod = innerProduct(x1, x2) + shift;
double result = prod;
for (int i = 1; i < degree; i++) {
result *= prod;
}
return result;
}
}