polykernel.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 weka.core.EuclideanDistance;
import weka.core.Instance;

public class PolyKernel implements Symbol{
	private double[] parameters=new double[this.getParameterSize()];
	public boolean isTerminal(){
		return true;
	}
	public String getName(){
		return "k1";
	}
	public int getArity(){
		return 0;
	}
	public double eval(double[] argS){//<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 tempD=this.parameters[0];
		double tempIPAB=argE.InnerProduct(argIA, argIB);
		double tempIPAA=argE.InnerProduct(argIA, argIA);
		double tempIPBB=argE.InnerProduct(argIB, argIB);
	//	System.out.print("Inner: "+tempIP+" ");
	//	System.out.print(tempIPAB+" "+tempIPAA+" "+tempIPBB+" ");
		
		double AB= Math.pow(tempIPAB+1, tempD);//k(a,b)
		double AA= Math.pow(tempIPAA+1, tempD);//k(a,a)
		double BB= Math.pow(tempIPBB+1, tempD);//k(b,b)
		
	//	System.out.println("Poly");
		
		return AB/Math.sqrt(AA*BB);
	}
	public double getValue(double[] argD){//argD[0]
		double tempD=this.parameters[0];
		double AB= Math.pow(argD[0]+1, tempD);//k(a,b)
		double AA= Math.pow(argD[1]+1, tempD);//k(a,a)
		double BB= Math.pow(argD[2]+1, tempD);//k(b,b)
		
	//	System.out.println("Poly");
		
		return AB/Math.sqrt(AA*BB);
        
	}
	public double getValue(double[] argD,Instance argIA,Instance argIB){
		if(argIA.equals(argIB))
			return 1;
		return this.getValue(argD);
	}
	
}