As you can see, the JOONE engine encapsulates much of the complexities of neural network programming. The example presented here shows the basic process by which a neural network can be used. Though real-world implementations of neural networks will be much more complex, the basic process remains the same. Data is presented to the neural network for training, and then new patterns are presented for recognition. The example program provides a good starting point for exploration with JOONE. The complete example source file is shown in Listing 3.
Listing 3: The complete example
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import org.joone.engine.*;
import org.joone.engine.learning.*;
import org.joone.io.*;
/**
* Example: The XOR Problem with JOONE
*
* @author Jeff Heaton
* @version 1.0
*/
public class XorExample extends JFrame implements
ActionListener,NeuralNetListener {
FullSynapse t1,t2;
/**
* The train button.
*/
JButton btnTrain;
/**
* The run button.
*/
JButton btnRun;
/**
* The quit button.
*/
JButton btnQuit;
/**
* The name of the input file.
*/
JTextField inputFile;
/**
* The name of the result file.
*/
JTextField resultFile;
/**
* The status line.
*/
JLabel status;
/**
* Constructor. Set up the components.
*/
public XorExample()
{
setTitle("XOR Solution");
Container content = getContentPane();
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints c = new GridBagConstraints();
content.setLayout(gridbag);
c.fill = GridBagConstraints.NONE;
c.weightx = 1.0;
// Training input label
c.gridwidth = GridBagConstraints.REMAINDER; //end row
c.anchor = GridBagConstraints.NORTHWEST;
content.add(
new JLabel(
"Enter the name of the training input
file:"),c);
// Training input filename
c.gridwidth = GridBagConstraints.REMAINDER; //end row
c.anchor = GridBagConstraints.NORTHWEST;
content.add(
inputFile = new JTextField(40),c);
inputFile.setText("./train.txt");
// Training input label
c.gridwidth = GridBagConstraints.REMAINDER; //end row
c.anchor = GridBagConstraints.NORTHWEST;
content.add(
new JLabel("Enter the name of the result file:")
,c);
// Training input filename
c.gridwidth = GridBagConstraints.REMAINDER; //end row
c.anchor = GridBagConstraints.NORTHWEST;
content.add(
resultFile = new JTextField(40),c);
resultFile.setText("./result.txt");
// the button panel
JPanel buttonPanel = new JPanel(new FlowLayout());
buttonPanel.add(btnTrain = new JButton("Train"));
buttonPanel.add(btnRun = new JButton("Run"));
buttonPanel.add(btnQuit = new JButton("Quit"));
btnTrain.addActionListener(this);
btnRun.addActionListener(this);
btnQuit.addActionListener(this);
// Add the button panel
c.gridwidth = GridBagConstraints.REMAINDER; //end row
c.anchor = GridBagConstraints.CENTER;
content.add(buttonPanel,c);
// Training input label
c.gridwidth = GridBagConstraints.REMAINDER; //end row
c.anchor = GridBagConstraints.NORTHWEST;
content.add(
status = new JLabel("Click train to begin
training..."),c);
// adjust size and position
pack();
Toolkit toolkit = Toolkit.getDefaultToolkit();
Dimension d = toolkit.getScreenSize();
setLocation(
(int)(d.width-this.getSize().getWidth())/2,
(int)(d.height-this.getSize().getHeight())/2 );
setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
setResizable(false);
}
/**
* The main function, just display the JFrame.
*
* @param args No arguments are used.
*/
public static void main(String args[])
{
(new XorExample()).show(true);
}
/**
* Called when the user clicks one of the three
* buttons.
*
* @param e The event.
*/
public void actionPerformed(ActionEvent e)
{
if ( e.getSource()==btnQuit )
System.exit(0);
else if ( e.getSource()==btnTrain )
train();
else if ( e.getSource()==btnRun )
run();
}
/**
* Called when the user clicks the run button.
*/
protected void run()
{
output.removeOutputSynapse(trainer);
inputStream.resetInput();
samples.resetInput();
FileOutputSynapse results = new FileOutputSynapse();
results.setFileName(resultFile.getText());
results.setMonitor(monitor);
output.addOutputSynapse(results);
input.start();
hidden.start();
output.start();
trainer.start();
// number of rows (patterns) contained in the input file
monitor.setPatterns(4);
// How many times the net must be trained on the input
// patterns
monitor.setTotCicles(1);
// The net must be trained
monitor.setLearning(false);
// The net starts the training job
monitor.Go();
status.setText("Results written to " + resultFile.getText());
}
/**
* The input layer of neurons.
*/
SigmoidLayer input;
/**
* The hidden layer of neurons.
*/
SigmoidLayer hidden;
/**
* The output layer of neurons.
*/
SigmoidLayer output;
/**
* The monitor. Used to pass parameters to all of the
* JOONE objects.
*/
Monitor monitor;
/**
* The file input stream.
*/
FileInputSynapse inputStream;
/**
* Used to train the neural network.
*/
TeachingSynapse trainer;
/**
* The training data.
*/
FileInputSynapse samples;
/**
* Called when the user clicks the train button.
*/
protected void train()
{
// First, creates the three Layers
input = new SigmoidLayer();
hidden = new SigmoidLayer();
output = new SigmoidLayer();
input.setLayerName("input");
hidden.setLayerName("hidden");
output.setLayerName("output");
// sets their dimensions
input.setRows(2);
hidden.setRows(3);
output.setRows(1);
// Now create the two Synapses
// input -> hidden conn.
FullSynapse synapse_IH = new FullSynapse();
// hidden -> output conn.
FullSynapse synapse_HO = new FullSynapse();
synapse_IH.setName("IH");
synapse_HO.setName("HO");
t1=synapse_IH;
t2=synapse_HO;
// Connect the input layer with the hidden layer
input.addOutputSynapse(synapse_IH);
hidden.addInputSynapse(synapse_IH);
// Connect the hidden layer with the output layer
hidden.addOutputSynapse(synapse_HO);
output.addInputSynapse(synapse_HO);
// Create the Monitor object and set the learning parameters
monitor = new Monitor();
monitor.setLearningRate(0.8);
monitor.setMomentum(0.3);
// Pass the Monitor to all components
input.setMonitor(monitor);
hidden.setMonitor(monitor);
output.setMonitor(monitor);
// The application registers itself as monitor's listener
// so it can receive the notifications of termination from
// the net.
monitor.addNeuralNetListener(this);
inputStream = new FileInputSynapse();
// The first two columns contain the input values
inputStream.setFirstCol(1);
inputStream.setLastCol(2);
// This is the file that contains the input data
inputStream.setFileName(inputFile.getText());
input.addInputSynapse(inputStream);
trainer = new TeachingSynapse();
trainer.setMonitor(monitor);
// Setting of the file containing the desired responses,
// provided by a FileInputSynapse
samples = new FileInputSynapse();
samples.setFileName(inputFile.getText());
// The output values are on the third column of the file
samples.setFirstCol(3);
samples.setLastCol(3);
trainer.setDesired(samples);
// Connects the Teacher to the last layer of the net
output.addOutputSynapse(trainer);
// All the layers must be activated invoking their method
// start; the layers are implemented as Runnable objects, then
// they are allocated on separated threads. The threads will
// stop after training and will need to be restarted later.
input.start();
hidden.start();
output.start();
trainer.start();
// number of rows (patterns) contained in the input file
monitor.setPatterns(4);
// How many times the net must be trained on the input
// patterns
monitor.setTotCicles(20000);
// The net must be trained
monitor.setLearning(true);
// The net starts the training job
monitor.Go();
}
/**
* JOONE Callback: called when the neural network
* stops. Not used.
*
* @param e The JOONE event
*/
public void netStopped(NeuralNetEvent e) {
}
/**
* JOONE Callback: called to update the progress
* of the neural network. Used to update the
* status line.
*
* @param e The JOONE event
*/
public void cicleTerminated(NeuralNetEvent e) {
Monitor mon = (Monitor)e.getSource();
long c = mon.getCurrentCicle();
long cl = c / 1000;
// print the results every 1000 cycles
if ( (cl * 1000) == c )
status.setText(c + " cycles remaining - Error = "
+ mon.getGlobalError());
}
/**
* JOONE Callback: Called when the network
* is starting up. Not used.
*
* @param e The JOONE event.
*/
public void netStarted(NeuralNetEvent e) {
}
}
About the Author
Jeff Heaton is the author of Programming Spiders, Bots, and Aggregators in Java (Sybex, 2002). Jeff works as a software designer for the Reinsurance Group of America. Jeff has written three books and numerous magazine articles about computer programming. Jeff may be contacted through his Web site, http://www.jeffheaton.com.
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