gausskernel.java

代码是一个分类器的实现,其中使用了部分weka的源代码。可以将项目导入eclipse运行

package com.lqy.GEP;
import java.util.*;

import weka.core.EuclideanDistance;
import weka.core.Instance;
public class GaussKernel implements Symbol{
	private double[] parameters=new double[this.getParameterSize()];
	public boolean isTerminal(){
		return true;
	}
	public String getName(){
		return "k2";
	}
	public int getArity(){
		return 0;
	}
	public double eval(double[] argD){//<x1,x2>或||x1-x2||，视不同的核函数而论
	    return 0;
		
	}
	public int getParameterSize(){
		return 1;
	}
	public void setParameters(double[] argD){
		for(int i=0;i<this.getParameterSize();i++)
			this.parameters[i]=argD[i];
	}
	public double getValue(EuclideanMeasure argE,Instance argIA,Instance argIB){
		
		if(argIA.equals(argIB))
			return 1;
		
		double delta=this.parameters[0];
		double tempIP=argE.distanceInOriginalSpace(argIA, argIB,Double.MAX_VALUE);
	//	System.out.println("Gauss");
		return Math.pow(Math.E, (-1)*tempIP/(Math.pow(delta, 2)*2));
	}//Weka的欧氏距离类要求Instances的引用，所以在这里作为参数传递
	public double getValue(double[] argD){//argD是两个Instance在原空间的距离
		double delta=this.parameters[0];
		return Math.pow(Math.E, (-1)*argD[0]/(Math.pow(delta, 2)*2));
	}
	public double getValue(double[] argD,Instance argIA,Instance argIB){
		if(argIA.equals(argIB))
			return 1;
		return this.getValue(argD);
	}
}