testerrortype.java

来自「神经网络源代码,实现了一个BP神经网络,可以完成基于BP的神经网络算法.」· Java 代码 · 共 40 行

package net.openai.ai.nn.error;

import java.util.*;
import net.openai.ai.nn.network.*;
import net.openai.ai.nn.training.*;

public class TestErrorType extends ErrorType {

    public void calculateError(Network network) {
	TrainingSet trainingSet = network.getTrainingSet();
	Enumeration e = trainingSet.getElements();
	double sum = 0;
	double setSize = trainingSet.size();
	double outputSize = network.getOutputLayer().getSize();
	while(e.hasMoreElements()) {
	    TrainingElement element = (TrainingElement) e.nextElement();
	    Vector desiredOutput = element.getDesired();
	    Vector actualOutput = element.getOutput();
	    if(desiredOutput.size() != actualOutput.size()) {
		db("Desired output size does not match the actual output..."
		   + "\nError could not be calculated for this element");
		continue;
	    }
	    int size = desiredOutput.size();
	    for(int i = 0; i < size; i++) {
		String desiredString = (String) desiredOutput.elementAt(i);
		double desired = Double.parseDouble(desiredString);
		double actual 
		    = ((Double) actualOutput.elementAt(i)).doubleValue();
		double difference = desired - actual;
		double squaredDifference = Math.pow(difference, 2);
		sum += squaredDifference;
	    }
	}
	double error = sum/2;
	network.setError(error);
    }

}