weka.classifiers.functions.MultilayerPerceptron.java Source code

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Here is the source code for weka.classifiers.functions.MultilayerPerceptron.java

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/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU 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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 *    MultilayerPerceptron.java
 *    Copyright (C) 2000-2012 University of Waikato, Hamilton, New Zealand
 */

package weka.classifiers.functions;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Random;
import java.util.StringTokenizer;
import java.util.Vector;

import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;

import weka.classifiers.AbstractClassifier;
import weka.classifiers.Classifier;
import weka.classifiers.IterativeClassifier;
import weka.classifiers.functions.neural.LinearUnit;
import weka.classifiers.functions.neural.NeuralConnection;
import weka.classifiers.functions.neural.NeuralNode;
import weka.classifiers.functions.neural.SigmoidUnit;
import weka.core.*;
import weka.core.Capabilities.Capability;
import weka.filters.Filter;
import weka.filters.unsupervised.attribute.NominalToBinary;

/**
 * <!-- globalinfo-start -->A classifier that uses backpropagation to learn a multi-layer perceptron to classify instances.
 * The network can be built by hand or set up using a simple heuristic.
 * The network parameters can also be monitored and modified during training time.
 * The nodes in this network are all sigmoid (except for when the class
 * is numeric, in which case the output nodes become unthresholded linear units).
 * <p/>
 * <!-- globalinfo-end -->
 * 
 * <!-- options-start --> Valid options are:
 * <p/>
 * 
 * <pre>
 * -L &lt;learning rate&gt;
 *  Learning rate for the backpropagation algorithm.
 *  (Value should be between 0 - 1, Default = 0.3).
 * </pre>
 * 
 * <pre>
 * -M &lt;momentum&gt;
 *  Momentum rate for the backpropagation algorithm.
 *  (Value should be between 0 - 1, Default = 0.2).
 * </pre>
 * 
 * <pre>
 * -N &lt;number of epochs&gt;
 *  Number of epochs to train through.
 *  (Default = 500).
 * </pre>
 * 
 * <pre>
 * -V &lt;percentage size of validation set&gt;
 *  Percentage size of validation set to use to terminate
 *  training (if this is non zero it can pre-empt num of epochs.
 *  (Value should be between 0 - 100, Default = 0).
 * </pre>
 * 
 * <pre>
 * -S &lt;seed&gt;
 *  The value used to seed the random number generator
 *  (Value should be &gt;= 0 and and a long, Default = 0).
 * </pre>
 * 
 * <pre>
 * -E &lt;threshold for number of consecutive errors&gt;
 *  The number of consecutive increases of error allowed for validation
 *  testing before training terminates.
 *  (Value should be &gt; 0, Default = 20).
 * </pre>
 * 
 * <pre>
 * -G
 *  GUI will be opened.
 *  (Use this to bring up a GUI).
 * </pre>
 * 
 * <pre>
 * -A
 *  Autocreation of the network connections will NOT be done.
 *  (This will be ignored if -G is NOT set)
 * </pre>
 * 
 * <pre>
 * -B
 *  A NominalToBinary filter will NOT automatically be used.
 *  (Set this to not use a NominalToBinary filter).
 * </pre>
 * 
 * <pre>
 * -H &lt;comma separated numbers for nodes on each layer&gt;
 *  The hidden layers to be created for the network.
 *  (Value should be a list of comma separated Natural 
 *  numbers or the letters 'a' = (attribs + classes) / 2, 
 *  'i' = attribs, 'o' = classes, 't' = attribs .+ classes)
 *  for wildcard values, Default = a).
 * </pre>
 * 
 * <pre>
 * -C
 *  Normalizing a numeric class will NOT be done.
 *  (Set this to not normalize the class if it's numeric).
 * </pre>
 * 
 * <pre>
 * -I
 *  Normalizing the attributes will NOT be done.
 *  (Set this to not normalize the attributes).
 * </pre>
 * 
 * <pre>
 * -R
 *  Reseting the network will NOT be allowed.
 *  (Set this to not allow the network to reset).
 * </pre>
 * 
 * <pre>
 * -D
 *  Learning rate decay will occur.
 *  (Set this to cause the learning rate to decay).
 * </pre>
 * 
 * <!-- options-end -->
 * 
 * @author Malcolm Ware (mfw4@cs.waikato.ac.nz)
 * @version $Revision$
 */
public class MultilayerPerceptron extends AbstractClassifier
        implements OptionHandler, WeightedInstancesHandler, Randomizable, IterativeClassifier {

    /** for serialization */
    private static final long serialVersionUID = -5990607817048210779L;

    /**
     * Main method for testing this class.
     * 
     * @param argv should contain command line options (see setOptions)
     */
    public static void main(String[] argv) {
        runClassifier(new MultilayerPerceptron(), argv);
    }

    /**
     * This inner class is used to connect the nodes in the network up to the data
     * that they are classifying, Note that objects of this class are only
     * suitable to go on the attribute side or class side of the network and not
     * both.
     */
    protected class NeuralEnd extends NeuralConnection {

        /** for serialization */
        static final long serialVersionUID = 7305185603191183338L;

        /**
         * the value that represents the instance value this node represents. For an
         * input it is the attribute number, for an output, if nominal it is the
         * class value.
         */
        private int m_link;

        /** True if node is an input, False if it's an output. */
        private boolean m_input;

        /**
         * Constructor
         */
        public NeuralEnd(String id) {
            super(id);

            m_link = 0;
            m_input = true;

        }

        /**
         * Call this function to determine if the point at x,y is on the unit.
         * 
         * @param g The graphics context for font size info.
         * @param x The x coord.
         * @param y The y coord.
         * @param w The width of the display.
         * @param h The height of the display.
         * @return True if the point is on the unit, false otherwise.
         */
        @Override
        public boolean onUnit(Graphics g, int x, int y, int w, int h) {

            FontMetrics fm = g.getFontMetrics();
            int l = (int) (m_x * w) - fm.stringWidth(m_id) / 2;
            int t = (int) (m_y * h) - fm.getHeight() / 2;
            if (x < l || x > l + fm.stringWidth(m_id) + 4 || y < t
                    || y > t + fm.getHeight() + fm.getDescent() + 4) {
                return false;
            }
            return true;

        }

        /**
         * This will draw the node id to the graphics context.
         * 
         * @param g The graphics context.
         * @param w The width of the drawing area.
         * @param h The height of the drawing area.
         */
        @Override
        public void drawNode(Graphics g, int w, int h) {

            if ((m_type & PURE_INPUT) == PURE_INPUT) {
                g.setColor(Color.green);
            } else {
                g.setColor(Color.orange);
            }

            FontMetrics fm = g.getFontMetrics();
            int l = (int) (m_x * w) - fm.stringWidth(m_id) / 2;
            int t = (int) (m_y * h) - fm.getHeight() / 2;
            g.fill3DRect(l, t, fm.stringWidth(m_id) + 4, fm.getHeight() + fm.getDescent() + 4, true);
            g.setColor(Color.black);

            g.drawString(m_id, l + 2, t + fm.getHeight() + 2);

        }

        /**
         * Call this function to draw the node highlighted.
         * 
         * @param g The graphics context.
         * @param w The width of the drawing area.
         * @param h The height of the drawing area.
         */
        @Override
        public void drawHighlight(Graphics g, int w, int h) {

            g.setColor(Color.black);
            FontMetrics fm = g.getFontMetrics();
            int l = (int) (m_x * w) - fm.stringWidth(m_id) / 2;
            int t = (int) (m_y * h) - fm.getHeight() / 2;
            g.fillRect(l - 2, t - 2, fm.stringWidth(m_id) + 8, fm.getHeight() + fm.getDescent() + 8);
            drawNode(g, w, h);
        }

        /**
         * Call this to get the output value of this unit.
         * 
         * @param calculate True if the value should be calculated if it hasn't been
         *          already.
         * @return The output value, or NaN, if the value has not been calculated.
         */
        @Override
        public double outputValue(boolean calculate) {

            if (Double.isNaN(m_unitValue) && calculate) {
                if (m_input) {
                    if (m_currentInstance.isMissing(m_link)) {
                        m_unitValue = 0;
                    } else {

                        m_unitValue = m_currentInstance.value(m_link);
                    }
                } else {
                    // node is an output.
                    m_unitValue = 0;
                    for (int noa = 0; noa < m_numInputs; noa++) {
                        m_unitValue += m_inputList[noa].outputValue(true);

                    }
                    if (m_numeric && m_normalizeClass) {
                        // then scale the value;
                        // this scales linearly from between -1 and 1
                        m_unitValue = m_unitValue * m_attributeRanges[m_instances.classIndex()]
                                + m_attributeBases[m_instances.classIndex()];
                    }
                }
            }
            return m_unitValue;

        }

        /**
         * Call this to get the error value of this unit, which in this case is the
         * difference between the predicted class, and the actual class.
         * 
         * @param calculate True if the value should be calculated if it hasn't been
         *          already.
         * @return The error value, or NaN, if the value has not been calculated.
         */
        @Override
        public double errorValue(boolean calculate) {

            if (!Double.isNaN(m_unitValue) && Double.isNaN(m_unitError) && calculate) {

                if (m_input) {
                    m_unitError = 0;
                    for (int noa = 0; noa < m_numOutputs; noa++) {
                        m_unitError += m_outputList[noa].errorValue(true);
                    }
                } else {
                    if (m_currentInstance.classIsMissing()) {
                        m_unitError = .1;
                    } else if (m_instances.classAttribute().isNominal()) {
                        if (m_currentInstance.classValue() == m_link) {
                            m_unitError = 1 - m_unitValue;
                        } else {
                            m_unitError = 0 - m_unitValue;
                        }
                    } else if (m_numeric) {

                        if (m_normalizeClass) {
                            if (m_attributeRanges[m_instances.classIndex()] == 0) {
                                m_unitError = 0;
                            } else {
                                m_unitError = (m_currentInstance.classValue() - m_unitValue)
                                        / m_attributeRanges[m_instances.classIndex()];
                                // m_numericRange;

                            }
                        } else {
                            m_unitError = m_currentInstance.classValue() - m_unitValue;
                        }
                    }
                }
            }
            return m_unitError;
        }

        /**
         * Call this to reset the value and error for this unit, ready for the next
         * run. This will also call the reset function of all units that are
         * connected as inputs to this one. This is also the time that the update
         * for the listeners will be performed.
         */
        @Override
        public void reset() {

            if (!Double.isNaN(m_unitValue) || !Double.isNaN(m_unitError)) {
                m_unitValue = Double.NaN;
                m_unitError = Double.NaN;
                m_weightsUpdated = false;
                for (int noa = 0; noa < m_numInputs; noa++) {
                    m_inputList[noa].reset();
                }
            }
        }

        /**
         * Call this to have the connection save the current weights.
         */
        @Override
        public void saveWeights() {
            for (int i = 0; i < m_numInputs; i++) {
                m_inputList[i].saveWeights();
            }
        }

        /**
         * Call this to have the connection restore from the saved weights.
         */
        @Override
        public void restoreWeights() {
            for (int i = 0; i < m_numInputs; i++) {
                m_inputList[i].restoreWeights();
            }
        }

        /**
         * Call this function to set What this end unit represents.
         * 
         * @param input True if this unit is used for entering an attribute, False
         *          if it's used for determining a class value.
         * @param val The attribute number or class type that this unit represents.
         *          (for nominal attributes).
         */
        public void setLink(boolean input, int val) throws Exception {
            m_input = input;

            if (input) {
                m_type = PURE_INPUT;
            } else {
                m_type = PURE_OUTPUT;
            }
            if (val < 0 || (input && val > m_instances.numAttributes())
                    || (!input && m_instances.classAttribute().isNominal()
                            && val > m_instances.classAttribute().numValues())) {
                m_link = 0;
            } else {
                m_link = val;
            }
        }

        /**
         * @return link for this node.
         */
        public int getLink() {
            return m_link;
        }

        /**
         * Returns the revision string.
         * 
         * @return the revision
         */
        @Override
        public String getRevision() {
            return RevisionUtils.extract("$Revision$");
        }
    }

    /**
     * Inner class used to draw the nodes onto.(uses the node lists!!) This will
     * also handle the user input.
     */
    private class NodePanel extends JPanel implements RevisionHandler {

        /** for serialization */
        static final long serialVersionUID = -3067621833388149984L;

        /**
         * The constructor.
         */
        public NodePanel() {

            addMouseListener(new MouseAdapter() {

                @Override
                public void mousePressed(MouseEvent e) {

                    if (!m_stopped) {
                        return;
                    }
                    if ((e.getModifiers() & MouseEvent.BUTTON1_MASK) == MouseEvent.BUTTON1_MASK && !e.isAltDown()) {
                        Graphics g = NodePanel.this.getGraphics();
                        int x = e.getX();
                        int y = e.getY();
                        int w = NodePanel.this.getWidth();
                        int h = NodePanel.this.getHeight();
                        ArrayList<NeuralConnection> tmp = new ArrayList<NeuralConnection>(4);
                        for (int noa = 0; noa < m_numAttributes; noa++) {
                            if (m_inputs[noa].onUnit(g, x, y, w, h)) {
                                tmp.add(m_inputs[noa]);
                                selection(tmp, (e.getModifiers() & MouseEvent.CTRL_MASK) == MouseEvent.CTRL_MASK,
                                        true);
                                return;
                            }
                        }
                        for (int noa = 0; noa < m_numClasses; noa++) {
                            if (m_outputs[noa].onUnit(g, x, y, w, h)) {
                                tmp.add(m_outputs[noa]);
                                selection(tmp, (e.getModifiers() & MouseEvent.CTRL_MASK) == MouseEvent.CTRL_MASK,
                                        true);
                                return;
                            }
                        }
                        for (NeuralConnection m_neuralNode : m_neuralNodes) {
                            if (m_neuralNode.onUnit(g, x, y, w, h)) {
                                tmp.add(m_neuralNode);
                                selection(tmp, (e.getModifiers() & MouseEvent.CTRL_MASK) == MouseEvent.CTRL_MASK,
                                        true);
                                return;
                            }

                        }
                        NeuralNode temp = new NeuralNode(String.valueOf(m_nextId), m_random, m_sigmoidUnit);
                        m_nextId++;
                        temp.setX((double) e.getX() / w);
                        temp.setY((double) e.getY() / h);
                        tmp.add(temp);
                        addNode(temp);
                        selection(tmp, (e.getModifiers() & MouseEvent.CTRL_MASK) == MouseEvent.CTRL_MASK, true);
                    } else {
                        // then right click
                        Graphics g = NodePanel.this.getGraphics();
                        int x = e.getX();
                        int y = e.getY();
                        int w = NodePanel.this.getWidth();
                        int h = NodePanel.this.getHeight();
                        ArrayList<NeuralConnection> tmp = new ArrayList<NeuralConnection>(4);
                        for (int noa = 0; noa < m_numAttributes; noa++) {
                            if (m_inputs[noa].onUnit(g, x, y, w, h)) {
                                tmp.add(m_inputs[noa]);
                                selection(tmp, (e.getModifiers() & MouseEvent.CTRL_MASK) == MouseEvent.CTRL_MASK,
                                        false);
                                return;
                            }

                        }
                        for (int noa = 0; noa < m_numClasses; noa++) {
                            if (m_outputs[noa].onUnit(g, x, y, w, h)) {
                                tmp.add(m_outputs[noa]);
                                selection(tmp, (e.getModifiers() & MouseEvent.CTRL_MASK) == MouseEvent.CTRL_MASK,
                                        false);
                                return;
                            }
                        }
                        for (NeuralConnection m_neuralNode : m_neuralNodes) {
                            if (m_neuralNode.onUnit(g, x, y, w, h)) {
                                tmp.add(m_neuralNode);
                                selection(tmp, (e.getModifiers() & MouseEvent.CTRL_MASK) == MouseEvent.CTRL_MASK,
                                        false);
                                return;
                            }
                        }
                        selection(null, (e.getModifiers() & MouseEvent.CTRL_MASK) == MouseEvent.CTRL_MASK, false);
                    }
                }
            });
        }

        /**
         * This function gets called when the user has clicked something It will
         * amend the current selection or connect the current selection to the new
         * selection. Or if nothing was selected and the right button was used it
         * will delete the node.
         * 
         * @param v The units that were selected.
         * @param ctrl True if ctrl was held down.
         * @param left True if it was the left mouse button.
         */
        private void selection(ArrayList<NeuralConnection> v, boolean ctrl, boolean left) {

            if (v == null) {
                // then unselect all.
                m_selected.clear();
                repaint();
                return;
            }

            // then exclusive or the new selection with the current one.
            if ((ctrl || m_selected.size() == 0) && left) {
                boolean removed = false;
                for (int noa = 0; noa < v.size(); noa++) {
                    removed = false;
                    for (int nob = 0; nob < m_selected.size(); nob++) {
                        if (v.get(noa) == m_selected.get(nob)) {
                            // then remove that element
                            m_selected.remove(nob);
                            removed = true;
                            break;
                        }
                    }
                    if (!removed) {
                        m_selected.add(v.get(noa));
                    }
                }
                repaint();
                return;
            }

            if (left) {
                // then connect the current selection to the new one.
                for (int noa = 0; noa < m_selected.size(); noa++) {
                    for (int nob = 0; nob < v.size(); nob++) {
                        NeuralConnection.connect(m_selected.get(noa), v.get(nob));
                    }
                }
            } else if (m_selected.size() > 0) {
                // then disconnect the current selection from the new one.

                for (int noa = 0; noa < m_selected.size(); noa++) {
                    for (int nob = 0; nob < v.size(); nob++) {
                        NeuralConnection.disconnect(m_selected.get(noa), v.get(nob));

                        NeuralConnection.disconnect(v.get(nob), m_selected.get(noa));

                    }
                }
            } else {
                // then remove the selected node. (it was right clicked while
                // no other units were selected
                for (int noa = 0; noa < v.size(); noa++) {
                    v.get(noa).removeAllInputs();
                    v.get(noa).removeAllOutputs();
                    removeNode(v.get(noa));
                }
            }
            repaint();
        }

        /**
         * To make sure pane has appropriate size and scroll bars work correctly.
         */
        @Override
        public Dimension getPreferredSize() {

            return new Dimension(getWidth(),
                    Integer.max(getHeight(), Integer.max(25 * m_numAttributes, 25 * m_numClasses)));
        }

        /**
         * This will paint the nodes ontot the panel.
         * 
         * @param g The graphics context.
         */
        @Override
        public void paintComponent(Graphics g) {

            super.paintComponent(g);
            int x = getWidth();
            int y = getHeight();
            for (int noa = 0; noa < m_numAttributes; noa++) {
                m_inputs[noa].drawInputLines(g, x, y);
            }
            for (int noa = 0; noa < m_numClasses; noa++) {
                m_outputs[noa].drawInputLines(g, x, y);
                m_outputs[noa].drawOutputLines(g, x, y);
            }
            for (NeuralConnection m_neuralNode : m_neuralNodes) {
                m_neuralNode.drawInputLines(g, x, y);
            }
            for (int noa = 0; noa < m_numAttributes; noa++) {
                m_inputs[noa].drawNode(g, x, y);
            }
            for (int noa = 0; noa < m_numClasses; noa++) {
                m_outputs[noa].drawNode(g, x, y);
            }
            for (NeuralConnection m_neuralNode : m_neuralNodes) {
                m_neuralNode.drawNode(g, x, y);
            }

            for (int noa = 0; noa < m_selected.size(); noa++) {
                m_selected.get(noa).drawHighlight(g, x, y);
            }
        }

        /**
         * Returns the revision string.
         * 
         * @return the revision
         */
        @Override
        public String getRevision() {
            return RevisionUtils.extract("$Revision$");
        }
    }

    /**
     * This provides the basic controls for working with the neuralnetwork
     * 
     * @author Malcolm Ware (mfw4@cs.waikato.ac.nz)
     * @version $Revision$
     */
    class ControlPanel extends JPanel implements RevisionHandler {

        /** for serialization */
        static final long serialVersionUID = 7393543302294142271L;

        /** The start stop button. */
        public JButton m_startStop;

        /** The button to accept the network (even if it hasn't done all epochs. */
        public JButton m_acceptButton;

        /** A label to state the number of epochs processed so far. */
        public JPanel m_epochsLabel;

        /** A label to state the total number of epochs to be processed. */
        public JLabel m_totalEpochsLabel;

        /** A text field to allow the changing of the total number of epochs. */
        public JTextField m_changeEpochs;

        /** A label to state the learning rate. */
        public JLabel m_learningLabel;

        /** A label to state the momentum. */
        public JLabel m_momentumLabel;

        /** A text field to allow the changing of the learning rate. */
        public JTextField m_changeLearning;

        /** A text field to allow the changing of the momentum. */
        public JTextField m_changeMomentum;

        /**
         * A label to state roughly the accuracy of the network.(because the
         * accuracy is calculated per epoch, but the network is changing throughout
         * each epoch train).
         */
        public JPanel m_errorLabel;

        /** The constructor. */
        public ControlPanel() {
            setBorder(BorderFactory.createTitledBorder("Controls"));

            m_totalEpochsLabel = new JLabel("Num Of Epochs  ");
            m_epochsLabel = new JPanel() {
                /** for serialization */
                private static final long serialVersionUID = 2562773937093221399L;

                @Override
                public void paintComponent(Graphics g) {
                    super.paintComponent(g);
                    g.setColor(m_controlPanel.m_totalEpochsLabel.getForeground());
                    g.drawString("Epoch  " + m_epoch, 0, 10);
                }
            };
            m_epochsLabel.setFont(m_totalEpochsLabel.getFont());

            m_changeEpochs = new JTextField();
            m_changeEpochs.setText("" + m_numEpochs);
            m_errorLabel = new JPanel() {
                /** for serialization */
                private static final long serialVersionUID = 4390239056336679189L;

                @Override
                public void paintComponent(Graphics g) {
                    super.paintComponent(g);
                    g.setColor(m_controlPanel.m_totalEpochsLabel.getForeground());
                    if (m_valSize == 0) {
                        g.drawString("Error per Epoch = " + Utils.doubleToString(m_error, 7), 0, 10);
                    } else {
                        g.drawString("Validation Error per Epoch = " + Utils.doubleToString(m_error, 7), 0, 10);
                    }
                }
            };
            m_errorLabel.setFont(m_epochsLabel.getFont());

            m_learningLabel = new JLabel("Learning Rate = ");
            m_momentumLabel = new JLabel("Momentum = ");
            m_changeLearning = new JTextField();
            m_changeMomentum = new JTextField();
            m_changeLearning.setText("" + m_learningRate);
            m_changeMomentum.setText("" + m_momentum);
            setLayout(new BorderLayout(15, 10));

            m_stopIt = true;
            m_accepted = false;
            m_startStop = new JButton("Start");
            m_startStop.setActionCommand("Start");

            m_acceptButton = new JButton("Accept");
            m_acceptButton.setActionCommand("Accept");

            JPanel buttons = new JPanel();
            buttons.setLayout(new BoxLayout(buttons, BoxLayout.Y_AXIS));
            buttons.add(m_startStop);
            buttons.add(m_acceptButton);
            add(buttons, BorderLayout.WEST);
            JPanel data = new JPanel();
            data.setLayout(new BoxLayout(data, BoxLayout.Y_AXIS));

            Box ab = new Box(BoxLayout.X_AXIS);
            ab.add(m_epochsLabel);
            data.add(ab);

            ab = new Box(BoxLayout.X_AXIS);
            Component b = Box.createGlue();
            ab.add(m_totalEpochsLabel);
            ab.add(m_changeEpochs);
            m_changeEpochs.setMaximumSize(new Dimension(200, 20));
            ab.add(b);
            data.add(ab);

            ab = new Box(BoxLayout.X_AXIS);
            ab.add(m_errorLabel);
            data.add(ab);

            add(data, BorderLayout.CENTER);

            data = new JPanel();
            data.setLayout(new BoxLayout(data, BoxLayout.Y_AXIS));
            ab = new Box(BoxLayout.X_AXIS);
            b = Box.createGlue();
            ab.add(m_learningLabel);
            ab.add(m_changeLearning);
            m_changeLearning.setMaximumSize(new Dimension(200, 20));
            ab.add(b);
            data.add(ab);

            ab = new Box(BoxLayout.X_AXIS);
            b = Box.createGlue();
            ab.add(m_momentumLabel);
            ab.add(m_changeMomentum);
            m_changeMomentum.setMaximumSize(new Dimension(200, 20));
            ab.add(b);
            data.add(ab);

            add(data, BorderLayout.EAST);

            m_startStop.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    if (e.getActionCommand().equals("Start")) {
                        m_stopIt = false;
                        m_startStop.setText("Stop");
                        m_startStop.setActionCommand("Stop");
                        int n = Integer.valueOf(m_changeEpochs.getText()).intValue();

                        m_numEpochs = n;
                        m_changeEpochs.setText("" + m_numEpochs);

                        double m = Double.valueOf(m_changeLearning.getText()).doubleValue();
                        setLearningRate(m);
                        m_changeLearning.setText("" + m_learningRate);

                        m = Double.valueOf(m_changeMomentum.getText()).doubleValue();
                        setMomentum(m);
                        m_changeMomentum.setText("" + m_momentum);

                        blocker(false);
                    } else if (e.getActionCommand().equals("Stop")) {
                        m_stopIt = true;
                        m_startStop.setText("Start");
                        m_startStop.setActionCommand("Start");
                    }
                }
            });

            m_acceptButton.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    m_accepted = true;
                    blocker(false);
                }
            });

            m_changeEpochs.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    int n = Integer.valueOf(m_changeEpochs.getText()).intValue();
                    if (n > 0) {
                        m_numEpochs = n;
                        blocker(false);
                    }
                }
            });
        }

        /**
         * Returns the revision string.
         * 
         * @return the revision
         */
        @Override
        public String getRevision() {
            return RevisionUtils.extract("$Revision$");
        }
    }

    /**
     * a ZeroR model in case no model can be built from the data or the network
     * predicts all zeros for the classes
     */
    private Classifier m_ZeroR;

    /** Whether to use the default ZeroR model */
    private boolean m_useDefaultModel = false;

    /** The training instances. */
    private Instances m_instances;

    /** The current instance running through the network. */
    private Instance m_currentInstance;

    /** A flag to say that it's a numeric class. */
    private boolean m_numeric;

    /** The ranges for all the attributes. */
    private double[] m_attributeRanges;

    /** The base values for all the attributes. */
    private double[] m_attributeBases;

    /** The output units.(only feeds the errors, does no calcs) */
    private NeuralEnd[] m_outputs;

    /** The input units.(only feeds the inputs does no calcs) */
    private NeuralEnd[] m_inputs;

    /** All the nodes that actually comprise the logical neural net. */
    private NeuralConnection[] m_neuralNodes;

    /** The number of classes. */
    private int m_numClasses = 0;

    /** The number of attributes. */
    private int m_numAttributes = 0; // note the number doesn't include the class.

    /** The panel the nodes are displayed on. */
    private NodePanel m_nodePanel;

    /** The control panel. */
    private ControlPanel m_controlPanel;

    /** The next id number available for default naming. */
    private int m_nextId;

    /** A Vector list of the units currently selected. */
    private ArrayList<NeuralConnection> m_selected;

    /** The number of epochs to train through. */
    private int m_numEpochs;

    /** a flag to state if the network should be running, or stopped. */
    private boolean m_stopIt;

    /** a flag to state that the network has in fact stopped. */
    private boolean m_stopped;

    /** a flag to state that the network should be accepted the way it is. */
    private boolean m_accepted;
    /** The window for the network. */
    private JFrame m_win;

    /**
     * A flag to tell the build classifier to automatically build a neural net.
     */
    private boolean m_autoBuild;

    /**
     * A flag to state that the gui for the network should be brought up. To allow
     * interaction while training.
     */
    private boolean m_gui;

    /** An int to say how big the validation set should be. */
    private int m_valSize;

    /** The number to to use to quit on validation testing. */
    private int m_driftThreshold;

    /** The number used to seed the random number generator. */
    private int m_randomSeed;

    /** The actual random number generator. */
    private Random m_random;

    /** A flag to state that a nominal to binary filter should be used. */
    private boolean m_useNomToBin;

    /** The actual filter. */
    private NominalToBinary m_nominalToBinaryFilter;

    /** The string that defines the hidden layers */
    private String m_hiddenLayers;

    /** This flag states that the user wants the input values normalized. */
    private boolean m_normalizeAttributes;

    /** This flag states that the user wants the learning rate to decay. */
    private boolean m_decay;

    /** This is the learning rate for the network. */
    private double m_learningRate;

    /** This is the momentum for the network. */
    private double m_momentum;

    /** Shows the number of the epoch that the network just finished. */
    private int m_epoch;

    /** Number of iterations (epochs) performed in this session of iterating */
    private int m_numItsPerformed;

    /** Shows the error of the epoch that the network just finished. */
    private double m_error;

    /**
     * This flag states that the user wants the network to restart if it is found
     * to be generating infinity or NaN for the error value. This would restart
     * the network with the current options except that the learning rate would be
     * smaller than before, (perhaps half of its current value). This option will
     * not be available if the gui is chosen (if the gui is open the user can fix
     * the network themselves, it is an architectural minefield for the network to
     * be reset with the gui open).
     */
    private boolean m_reset;

    /**
     * This flag states that the user wants the class to be normalized while
     * processing in the network is done. (the final answer will be in the
     * original range regardless). This option will only be used when the class is
     * numeric.
     */
    private boolean m_normalizeClass;

    /**
     * this is a sigmoid unit.
     */
    private final SigmoidUnit m_sigmoidUnit;

    /**
     * This is a linear unit.
     */
    private final LinearUnit m_linearUnit;

    /**
     * Whether to allow training to continue at a later point after the initial
     * model is built.
     */
    protected boolean m_resume;

    /**
     * The constructor.
     */
    public MultilayerPerceptron() {
        m_instances = null;
        m_currentInstance = null;
        m_controlPanel = null;
        m_nodePanel = null;
        m_epoch = 0;
        m_error = 0;

        m_outputs = new NeuralEnd[0];
        m_inputs = new NeuralEnd[0];
        m_numAttributes = 0;
        m_numClasses = 0;
        m_neuralNodes = new NeuralConnection[0];
        m_selected = new ArrayList<NeuralConnection>(4);
        m_nextId = 0;
        m_stopIt = true;
        m_stopped = true;
        m_accepted = false;
        m_numeric = false;
        m_random = null;
        m_nominalToBinaryFilter = new NominalToBinary();
        m_sigmoidUnit = new SigmoidUnit();
        m_linearUnit = new LinearUnit();
        // setting all the options to their defaults. To completely change these
        // defaults they will also need to be changed down the bottom in the
        // setoptions function (the text info in the accompanying functions should
        // also be changed to reflect the new defaults
        m_normalizeClass = true;
        m_normalizeAttributes = true;
        m_autoBuild = true;
        m_gui = false;
        m_useNomToBin = true;
        m_driftThreshold = 20;
        m_numEpochs = 500;
        m_valSize = 0;
        m_randomSeed = 0;
        m_hiddenLayers = "a";
        m_learningRate = .3;
        m_momentum = .2;
        m_reset = true;
        m_decay = false;
    }

    /**
     * @param d True if the learning rate should decay.
     */
    public void setDecay(boolean d) {
        m_decay = d;
    }

    /**
     * @return the flag for having the learning rate decay.
     */
    public boolean getDecay() {
        return m_decay;
    }

    /**
     * This sets the network up to be able to reset itself with the current
     * settings and the learning rate at half of what it is currently. This will
     * only happen if the network creates NaN or infinite errors. Also this will
     * continue to happen until the network is trained properly. The learning rate
     * will also get set back to it's original value at the end of this. This can
     * only be set to true if the GUI is not brought up.
     * 
     * @param r True if the network should restart with it's current options and
     *          set the learning rate to half what it currently is.
     */
    public void setReset(boolean r) {
        if (m_gui) {
            r = false;
        }
        m_reset = r;

    }

    /**
     * @return The flag for reseting the network.
     */
    public boolean getReset() {
        return m_reset;
    }

    /**
     * @param c True if the class should be normalized (the class will only ever
     *          be normalized if it is numeric). (Normalization puts the range
     *          between -1 - 1).
     */
    public void setNormalizeNumericClass(boolean c) {
        m_normalizeClass = c;
    }

    /**
     * @return The flag for normalizing a numeric class.
     */
    public boolean getNormalizeNumericClass() {
        return m_normalizeClass;
    }

    /**
     * @param a True if the attributes should be normalized (even nominal
     *          attributes will get normalized here) (range goes between -1 - 1).
     */
    public void setNormalizeAttributes(boolean a) {
        m_normalizeAttributes = a;
    }

    /**
     * @return The flag for normalizing attributes.
     */
    public boolean getNormalizeAttributes() {
        return m_normalizeAttributes;
    }

    /**
     * @param f True if a nominalToBinary filter should be used on the data.
     */
    public void setNominalToBinaryFilter(boolean f) {
        m_useNomToBin = f;
    }

    /**
     * @return The flag for nominal to binary filter use.
     */
    public boolean getNominalToBinaryFilter() {
        return m_useNomToBin;
    }

    /**
     * This seeds the random number generator, that is used when a random number
     * is needed for the network.
     * 
     * @param l The seed.
     */
    @Override
    public void setSeed(int l) {
        if (l >= 0) {
            m_randomSeed = l;
        }
    }

    /**
     * @return The seed for the random number generator.
     */
    @Override
    public int getSeed() {
        return m_randomSeed;
    }

    /**
     * This sets the threshold to use for when validation testing is being done.
     * It works by ending testing once the error on the validation set has
     * consecutively increased a certain number of times.
     * 
     * @param t The threshold to use for this.
     */
    public void setValidationThreshold(int t) {
        if (t > 0) {
            m_driftThreshold = t;
        }
    }

    /**
     * @return The threshold used for validation testing.
     */
    public int getValidationThreshold() {
        return m_driftThreshold;
    }

    /**
     * The learning rate can be set using this command. NOTE That this is a static
     * variable so it affect all networks that are running. Must be greater than 0
     * and no more than 1.
     * 
     * @param l The New learning rate.
     */
    public void setLearningRate(double l) {
        if (l > 0 && l <= 1) {
            m_learningRate = l;

            if (m_controlPanel != null) {
                m_controlPanel.m_changeLearning.setText("" + l);
            }
        }
    }

    /**
     * @return The learning rate for the nodes.
     */
    public double getLearningRate() {
        return m_learningRate;
    }

    /**
     * The momentum can be set using this command. THE same conditions apply to
     * this as to the learning rate.
     * 
     * @param m The new Momentum.
     */
    public void setMomentum(double m) {
        if (m >= 0 && m <= 1) {
            m_momentum = m;

            if (m_controlPanel != null) {
                m_controlPanel.m_changeMomentum.setText("" + m);
            }
        }
    }

    /**
     * @return The momentum for the nodes.
     */
    public double getMomentum() {
        return m_momentum;
    }

    /**
     * This will set whether the network is automatically built or if it is left
     * up to the user. (there is nothing to stop a user from altering an autobuilt
     * network however).
     * 
     * @param a True if the network should be auto built.
     */
    public void setAutoBuild(boolean a) {
        if (!m_gui) {
            a = true;
        }
        m_autoBuild = a;
    }

    /**
     * @return The auto build state.
     */
    public boolean getAutoBuild() {
        return m_autoBuild;
    }

    /**
     * This will set what the hidden layers are made up of when auto build is
     * enabled. Note to have no hidden units, just put a single 0, Any more 0's
     * will indicate that the string is badly formed and make it unaccepted.
     * Negative numbers, and floats will do the same. There are also some
     * wildcards. These are 'a' = (number of attributes + number of classes) / 2,
     * 'i' = number of attributes, 'o' = number of classes, and 't' = number of
     * attributes + number of classes.
     * 
     * @param h A string with a comma seperated list of numbers. Each number is
     *          the number of nodes to be on a hidden layer.
     */
    public void setHiddenLayers(String h) {
        String tmp = "";
        StringTokenizer tok = new StringTokenizer(h, ",");
        if (tok.countTokens() == 0) {
            return;
        }
        double dval;
        int val;
        String c;
        boolean first = true;
        while (tok.hasMoreTokens()) {
            c = tok.nextToken().trim();

            if (c.equals("a") || c.equals("i") || c.equals("o") || c.equals("t")) {
                tmp += c;
            } else {
                dval = Double.valueOf(c).doubleValue();
                val = (int) dval;

                if ((val == dval && (val != 0 || (tok.countTokens() == 0 && first)) && val >= 0)) {
                    tmp += val;
                } else {
                    return;
                }
            }

            first = false;
            if (tok.hasMoreTokens()) {
                tmp += ", ";
            }
        }
        m_hiddenLayers = tmp;
    }

    /**
     * @return A string representing the hidden layers, each number is the number
     *         of nodes on a hidden layer.
     */
    public String getHiddenLayers() {
        return m_hiddenLayers;
    }

    /**
     * This will set whether A GUI is brought up to allow interaction by the user
     * with the neural network during training.
     * 
     * @param a True if gui should be created.
     */
    public void setGUI(boolean a) {
        m_gui = a;
        if (!a) {
            setAutoBuild(true);

        } else {
            setReset(false);
        }
    }

    /**
     * @return The true if should show gui.
     */
    public boolean getGUI() {
        return m_gui;
    }

    /**
     * This will set the size of the validation set.
     * 
     * @param a The size of the validation set, as a percentage of the whole.
     */
    public void setValidationSetSize(int a) {
        if (a < 0 || a > 99) {
            return;
        }
        m_valSize = a;
    }

    /**
     * @return The percentage size of the validation set.
     */
    public int getValidationSetSize() {
        return m_valSize;
    }

    /**
     * Set the number of training epochs to perform. Must be greater than 0.
     * 
     * @param n The number of epochs to train through.
     */
    public void setTrainingTime(int n) {
        if (n > 0) {
            m_numEpochs = n;
        }
    }

    /**
     * @return The number of epochs to train through.
     */
    public int getTrainingTime() {
        return m_numEpochs;
    }

    /**
     * Call this function to place a node into the network list.
     * 
     * @param n The node to place in the list.
     */
    private void addNode(NeuralConnection n) {

        NeuralConnection[] temp1 = new NeuralConnection[m_neuralNodes.length + 1];
        for (int noa = 0; noa < m_neuralNodes.length; noa++) {
            temp1[noa] = m_neuralNodes[noa];
        }

        temp1[temp1.length - 1] = n;
        m_neuralNodes = temp1;
    }

    /**
     * Call this function to remove the passed node from the list. This will only
     * remove the node if it is in the neuralnodes list.
     * 
     * @param n The neuralConnection to remove.
     * @return True if removed false if not (because it wasn't there).
     */
    private boolean removeNode(NeuralConnection n) {
        NeuralConnection[] temp1 = new NeuralConnection[m_neuralNodes.length - 1];
        int skip = 0;
        for (int noa = 0; noa < m_neuralNodes.length; noa++) {
            if (n == m_neuralNodes[noa]) {
                skip++;
            } else if (!((noa - skip) >= temp1.length)) {
                temp1[noa - skip] = m_neuralNodes[noa];
            } else {
                return false;
            }
        }
        m_neuralNodes = temp1;
        return true;
    }

    /**
     * This function sets what the m_numeric flag to represent the passed class it
     * also performs the normalization of the attributes if applicable and sets up
     * the info to normalize the class. (note that regardless of the options it
     * will fill an array with the range and base, set to normalize all attributes
     * and the class to be between -1 and 1)
     * 
     * @param inst the instances.
     * @return The modified instances. This needs to be done. If the attributes
     *         are normalized then deep copies will be made of all the instances
     *         which will need to be passed back out.
     */
    private Instances setClassType(Instances inst) throws Exception {
        if (inst != null) {
            // x bounds
            m_attributeRanges = new double[inst.numAttributes()];
            m_attributeBases = new double[inst.numAttributes()];
            for (int noa = 0; noa < inst.numAttributes(); noa++) {
                double min = Double.POSITIVE_INFINITY;
                double max = Double.NEGATIVE_INFINITY;
                for (int i = 0; i < inst.numInstances(); i++) {
                    if (!inst.instance(i).isMissing(noa)) {
                        double value = inst.instance(i).value(noa);
                        if (value < min) {
                            min = value;
                        }
                        if (value > max) {
                            max = value;
                        }
                    }
                }
                m_attributeRanges[noa] = (max - min) / 2;
                m_attributeBases[noa] = (max + min) / 2;
            }

            if (m_normalizeAttributes) {
                for (int i = 0; i < inst.numInstances(); i++) {
                    Instance currentInstance = inst.instance(i);
                    double[] instance = new double[inst.numAttributes()];
                    for (int noa = 0; noa < inst.numAttributes(); noa++) {
                        if (noa != inst.classIndex()) {
                            if (m_attributeRanges[noa] != 0) {
                                instance[noa] = (currentInstance.value(noa) - m_attributeBases[noa])
                                        / m_attributeRanges[noa];
                            } else {
                                instance[noa] = currentInstance.value(noa) - m_attributeBases[noa];
                            }
                        } else {
                            instance[noa] = currentInstance.value(noa);
                        }
                    }
                    inst.set(i, new DenseInstance(currentInstance.weight(), instance));
                }
            }

            if (inst.classAttribute().isNumeric()) {
                m_numeric = true;
            } else {
                m_numeric = false;
            }
        }
        return inst;
    }

    /**
     * A function used to stop the code that called buildclassifier from
     * continuing on before the user has finished the decision tree.
     * 
     * @param tf True to stop the thread, False to release the thread that is
     *          waiting there (if one).
     */
    public synchronized void blocker(boolean tf) {
        if (tf) {
            try {
                wait();
            } catch (InterruptedException e) {
            }
        } else {
            notifyAll();
        }
    }

    /**
     * Call this function to update the control panel for the gui.
     */
    private void updateDisplay() {

        if (m_gui) {
            m_controlPanel.m_errorLabel.repaint();
            m_controlPanel.m_epochsLabel.repaint();
        }
    }

    /**
     * this will reset all the nodes in the network.
     */
    private void resetNetwork() {
        for (int noc = 0; noc < m_numClasses; noc++) {
            m_outputs[noc].reset();
        }
    }

    /**
     * This will cause the output values of all the nodes to be calculated. Note
     * that the m_currentInstance is used to calculate these values.
     */
    private void calculateOutputs() {
        for (int noc = 0; noc < m_numClasses; noc++) {
            // get the values.
            m_outputs[noc].outputValue(true);
        }
    }

    /**
     * This will cause the error values to be calculated for all nodes. Note that
     * the m_currentInstance is used to calculate these values. Also the output
     * values should have been calculated first.
     * 
     * @return The squared error.
     */
    private double calculateErrors() throws Exception {
        double ret = 0, temp = 0;
        for (int noc = 0; noc < m_numAttributes; noc++) {
            // get the errors.
            m_inputs[noc].errorValue(true);

        }
        for (int noc = 0; noc < m_numClasses; noc++) {
            temp = m_outputs[noc].errorValue(false);
            ret += temp * temp;
        }
        return ret;

    }

    /**
     * This will cause the weight values to be updated based on the learning rate,
     * momentum and the errors that have been calculated for each node.
     * 
     * @param l The learning rate to update with.
     * @param m The momentum to update with.
     */
    private void updateNetworkWeights(double l, double m) {
        for (int noc = 0; noc < m_numClasses; noc++) {
            // update weights
            m_outputs[noc].updateWeights(l, m);
        }

    }

    /**
     * This creates the required input units.
     */
    private void setupInputs() throws Exception {
        m_inputs = new NeuralEnd[m_numAttributes];
        int now = 0;
        for (int noa = 0; noa < m_numAttributes + 1; noa++) {
            if (m_instances.classIndex() != noa) {
                m_inputs[noa - now] = new NeuralEnd(m_instances.attribute(noa).name());

                m_inputs[noa - now].setX(.1);
                m_inputs[noa - now].setY((noa - now + 1.0) / (m_numAttributes + 1));
                m_inputs[noa - now].setLink(true, noa);
            } else {
                now = 1;
            }
        }

    }

    /**
     * This creates the required output units.
     */
    private void setupOutputs() throws Exception {

        m_outputs = new NeuralEnd[m_numClasses];
        for (int noa = 0; noa < m_numClasses; noa++) {
            if (m_numeric) {
                m_outputs[noa] = new NeuralEnd(m_instances.classAttribute().name());
            } else {
                m_outputs[noa] = new NeuralEnd(m_instances.classAttribute().value(noa));
            }

            m_outputs[noa].setX(.9);
            m_outputs[noa].setY((noa + 1.0) / (m_numClasses + 1));
            m_outputs[noa].setLink(false, noa);
            NeuralNode temp = new NeuralNode(String.valueOf(m_nextId), m_random, m_sigmoidUnit);
            m_nextId++;
            temp.setX(.75);
            temp.setY((noa + 1.0) / (m_numClasses + 1));
            addNode(temp);
            NeuralConnection.connect(temp, m_outputs[noa]);
        }

    }

    /**
     * Call this function to automatically generate the hidden units
     */
    private void setupHiddenLayer() {
        StringTokenizer tok = new StringTokenizer(m_hiddenLayers, ",");
        int val = 0; // num of nodes in a layer
        int prev = 0; // used to remember the previous layer
        int num = tok.countTokens(); // number of layers
        String c;
        for (int noa = 0; noa < num; noa++) {
            // note that I am using the Double to get the value rather than the
            // Integer class, because for some reason the Double implementation can
            // handle leading white space and the integer version can't!?!
            c = tok.nextToken().trim();
            if (c.equals("a")) {
                val = (m_numAttributes + m_numClasses) / 2;
            } else if (c.equals("i")) {
                val = m_numAttributes;
            } else if (c.equals("o")) {
                val = m_numClasses;
            } else if (c.equals("t")) {
                val = m_numAttributes + m_numClasses;
            } else {
                val = Double.valueOf(c).intValue();
            }
            for (int nob = 0; nob < val; nob++) {
                NeuralNode temp = new NeuralNode(String.valueOf(m_nextId), m_random, m_sigmoidUnit);
                m_nextId++;
                temp.setX(.5 / (num) * noa + .25);
                temp.setY((nob + 1.0) / (val + 1));
                addNode(temp);
                if (noa > 0) {
                    // then do connections
                    for (int noc = m_neuralNodes.length - nob - 1 - prev; noc < m_neuralNodes.length - nob
                            - 1; noc++) {
                        NeuralConnection.connect(m_neuralNodes[noc], temp);
                    }
                }
            }
            prev = val;
        }
        tok = new StringTokenizer(m_hiddenLayers, ",");
        c = tok.nextToken();
        if (c.equals("a")) {
            val = (m_numAttributes + m_numClasses) / 2;
        } else if (c.equals("i")) {
            val = m_numAttributes;
        } else if (c.equals("o")) {
            val = m_numClasses;
        } else if (c.equals("t")) {
            val = m_numAttributes + m_numClasses;
        } else {
            val = Double.valueOf(c).intValue();
        }

        if (val == 0) {
            for (int noa = 0; noa < m_numAttributes; noa++) {
                for (int nob = 0; nob < m_numClasses; nob++) {
                    NeuralConnection.connect(m_inputs[noa], m_neuralNodes[nob]);
                }
            }
        } else {
            for (int noa = 0; noa < m_numAttributes; noa++) {
                for (int nob = m_numClasses; nob < m_numClasses + val; nob++) {
                    NeuralConnection.connect(m_inputs[noa], m_neuralNodes[nob]);
                }
            }
            for (int noa = m_neuralNodes.length - prev; noa < m_neuralNodes.length; noa++) {
                for (int nob = 0; nob < m_numClasses; nob++) {
                    NeuralConnection.connect(m_neuralNodes[noa], m_neuralNodes[nob]);
                }
            }
        }

    }

    /**
     * This will go through all the nodes and check if they are connected to a
     * pure output unit. If so they will be set to be linear units. If not they
     * will be set to be sigmoid units.
     */
    private void setEndsToLinear() {
        for (NeuralConnection m_neuralNode : m_neuralNodes) {
            if ((m_neuralNode.getType() & NeuralConnection.OUTPUT) == NeuralConnection.OUTPUT) {
                ((NeuralNode) m_neuralNode).setMethod(m_linearUnit);
            } else {
                ((NeuralNode) m_neuralNode).setMethod(m_sigmoidUnit);
            }
        }
    }

    /**
     * Returns default capabilities of the classifier.
     * 
     * @return the capabilities of this classifier
     */
    @Override
    public Capabilities getCapabilities() {
        Capabilities result = super.getCapabilities();
        result.disableAll();

        // attributes
        result.enable(Capability.NOMINAL_ATTRIBUTES);
        result.enable(Capability.NUMERIC_ATTRIBUTES);
        result.enable(Capability.DATE_ATTRIBUTES);
        result.enable(Capability.MISSING_VALUES);

        // class
        result.enable(Capability.NOMINAL_CLASS);
        result.enable(Capability.NUMERIC_CLASS);
        result.enable(Capability.DATE_CLASS);
        result.enable(Capability.MISSING_CLASS_VALUES);

        return result;
    }

    /** The instances in the validation set (if any) */
    protected Instances valSet = null;

    /** The number of instances in the validation set (if any) */
    protected int numInVal = 0;

    /** Total weight of the instances in the training set */
    protected double totalWeight = 0;

    /** Total weight of the instances in the validation set (if any) */
    protected double totalValWeight = 0;

    /** Drift off counter */
    protected double driftOff = 0;

    /** To keep track of error */
    protected double lastRight = Double.POSITIVE_INFINITY;
    protected double bestError = Double.POSITIVE_INFINITY;

    /** Data in original format (in case learning rate gets reset */
    protected Instances originalFormatData = null;

    /**
     * Initializes an iterative classifier.
     *
     * @param data the instances to be used in induction
     * @exception Exception if the model cannot be initialized
     */
    @Override
    public void initializeClassifier(Instances data) throws Exception {

        m_numItsPerformed = 0;

        if (m_instances == null || m_instances.numInstances() == 0) {
            // can classifier handle the data?
            getCapabilities().testWithFail(data);

            // remove instances with missing class
            data = new Instances(data);
            data.deleteWithMissingClass();
            originalFormatData = data;

            m_ZeroR = new weka.classifiers.rules.ZeroR();
            m_ZeroR.buildClassifier(data);
            // only class? -> use ZeroR model
            if (data.numAttributes() == 1) {
                System.err.println("Cannot build model (only class attribute present in data!), "
                        + "using ZeroR model instead!");
                m_useDefaultModel = true;
                return;
            } else {
                m_useDefaultModel = false;
            }

            m_epoch = 0;
            m_error = 0;
            m_instances = null;
            m_currentInstance = null;
            m_controlPanel = null;
            m_nodePanel = null;

            m_outputs = new NeuralEnd[0];
            m_inputs = new NeuralEnd[0];
            m_numAttributes = 0;
            m_numClasses = 0;
            m_neuralNodes = new NeuralConnection[0];

            m_selected = new ArrayList<NeuralConnection>(4);
            m_nextId = 0;
            m_stopIt = true;
            m_stopped = true;
            m_accepted = false;
            m_instances = new Instances(data);
            m_random = new Random(m_randomSeed);
            m_instances.randomize(m_random);

            if (m_useNomToBin) {
                m_nominalToBinaryFilter = new NominalToBinary();
                m_nominalToBinaryFilter.setInputFormat(m_instances);
                m_instances = Filter.useFilter(m_instances, m_nominalToBinaryFilter);
            }
            m_numAttributes = m_instances.numAttributes() - 1;
            m_numClasses = m_instances.numClasses();

            setClassType(m_instances);

            // this sets up the validation set.
            // numinval is needed later
            numInVal = (int) (m_valSize / 100.0 * m_instances.numInstances());
            if (m_valSize > 0) {
                if (numInVal == 0) {
                    numInVal = 1;
                }
                valSet = new Instances(m_instances, 0, numInVal);
            }
            // /////////

            setupInputs();

            setupOutputs();
            if (m_autoBuild) {
                setupHiddenLayer();
            }

            // ///////////////////////////
            // this sets up the gui for usage
            if (m_gui) {
                m_win = Utils.getWekaJFrame("Neural Network", null);

                m_win.addWindowListener(new WindowAdapter() {
                    @Override
                    public void windowClosing(WindowEvent e) {
                        boolean k = m_stopIt;
                        m_stopIt = true;
                        int well = JOptionPane.showConfirmDialog(m_win,
                                "Are You Sure...\n" + "Click Yes To Accept" + " The Neural Network"
                                        + "\n Click No To Return",
                                "Accept Neural Network", JOptionPane.YES_NO_OPTION);

                        if (well == 0) {
                            m_win.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                            m_accepted = true;
                            blocker(false);
                        } else {
                            m_win.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
                        }
                        m_stopIt = k;
                    }
                });

                m_win.getContentPane().setLayout(new BorderLayout());
                m_nodePanel = new NodePanel();
                // without the following two lines, the
                // NodePanel.paintComponents(Graphics)
                // method will go berserk if the network doesn't fit completely: it will
                // get called on a constant basis, using 100% of the CPU
                // see the following forum thread:
                // http://forum.java.sun.com/thread.jspa?threadID=580929&messageID=2945011
                m_nodePanel.setPreferredSize(new Dimension(640, 480));
                m_nodePanel.revalidate();

                JScrollPane sp = new JScrollPane(m_nodePanel, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
                        JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
                m_controlPanel = new ControlPanel();

                m_win.getContentPane().add(sp, BorderLayout.CENTER);
                m_win.getContentPane().add(m_controlPanel, BorderLayout.SOUTH);
                m_win.setSize(640, 480);
                m_win.setVisible(true);
            }

            // This sets up the initial state of the gui
            if (m_gui) {
                blocker(true);
                m_controlPanel.m_changeEpochs.setEnabled(false);
                m_controlPanel.m_changeLearning.setEnabled(false);
                m_controlPanel.m_changeMomentum.setEnabled(false);
            }

            // For silly situations in which the network gets accepted before training
            // commences
            if (m_numeric) {
                setEndsToLinear();
            }
            if (m_accepted) {
                return;
            }

            // connections done.

            totalWeight = 0;
            totalValWeight = 0;
            driftOff = 0;
            lastRight = Double.POSITIVE_INFINITY;
            bestError = Double.POSITIVE_INFINITY;

            // ensure that at least 1 instance is trained through.
            if (numInVal == m_instances.numInstances()) {
                numInVal--;
            }
            if (numInVal < 0) {
                numInVal = 0;
            }
            for (int noa = numInVal; noa < m_instances.numInstances(); noa++) {
                if (!m_instances.instance(noa).classIsMissing()) {
                    totalWeight += m_instances.instance(noa).weight();
                }
            }
            if (m_valSize != 0) {
                for (int noa = 0; noa < valSet.numInstances(); noa++) {
                    if (!valSet.instance(noa).classIsMissing()) {
                        totalValWeight += valSet.instance(noa).weight();
                    }
                }
            }
            m_stopped = false;
        }
    }

    /**
     * Performs one iteration.
     *
     * @return false if no further iterations could be performed, true otherwise
     * @exception Exception if this iteration fails for unexpected reasons
     */
    @Override
    public boolean next() throws Exception {

        if (m_accepted || m_useDefaultModel || m_instances.numInstances() == 0) { // Has user accepted the network already or do we need to use default model?
            return false;
        }
        m_epoch++;
        m_numItsPerformed++;
        double right = 0;
        for (int nob = numInVal; nob < m_instances.numInstances(); nob++) {
            m_currentInstance = m_instances.instance(nob);

            if (!m_currentInstance.classIsMissing()) {

                // this is where the network updating (and training occurs, for the
                // training set
                resetNetwork();
                calculateOutputs();
                double tempRate = m_learningRate * m_currentInstance.weight();
                if (m_decay) {
                    tempRate /= m_epoch;
                }

                right += (calculateErrors() / m_instances.numClasses()) * m_currentInstance.weight();
                updateNetworkWeights(tempRate, m_momentum);
            }
        }
        right /= totalWeight;
        if (Double.isInfinite(right) || Double.isNaN(right)) {
            if ((!m_reset) || (originalFormatData == null)) {
                m_instances = null;
                throw new Exception("Network cannot train. Try restarting with a smaller learning rate.");
            } else {
                // reset the network if possible
                if (m_learningRate <= Utils.SMALL) {
                    throw new IllegalStateException(
                            "Learning rate got too small (" + m_learningRate + " <= " + Utils.SMALL + ")!");
                }
                double origRate = m_learningRate; // only used for when reset
                m_learningRate /= 2;
                buildClassifier(originalFormatData);
                m_learningRate = origRate;
                return false;
            }
        }

        // //////////////////////do validation testing if applicable
        if (m_valSize != 0) {
            right = 0;
            if (valSet == null) {
                throw new IllegalArgumentException("Trying to use validation set but validation set is null.");
            }
            for (int nob = 0; nob < valSet.numInstances(); nob++) {
                m_currentInstance = valSet.instance(nob);
                if (!m_currentInstance.classIsMissing()) {
                    // this is where the network updating occurs, for the validation set
                    resetNetwork();
                    calculateOutputs();
                    right += (calculateErrors() / valSet.numClasses()) * m_currentInstance.weight();
                    // note 'right' could be calculated here just using
                    // the calculate output values. This would be faster.
                    // be less modular
                }
            }

            if (right < lastRight) {
                if (right < bestError) {
                    bestError = right;
                    // save the network weights at this point
                    for (int noc = 0; noc < m_numClasses; noc++) {
                        m_outputs[noc].saveWeights();
                    }
                    driftOff = 0;
                }
            } else {
                driftOff++;
            }
            lastRight = right;
            // if (driftOff > m_driftThreshold || m_epoch + 1 >= m_numEpochs) {
            if (driftOff > m_driftThreshold || m_numItsPerformed + 1 >= m_numEpochs) {
                for (int noc = 0; noc < m_numClasses; noc++) {
                    m_outputs[noc].restoreWeights();
                }
                m_accepted = true;
            }
            right /= totalValWeight;
        }
        m_error = right;
        // shows what the neuralnet is upto if a gui exists.
        updateDisplay();
        // This junction controls what state the gui is in at the end of each
        // epoch, Such as if it is paused, if it is resumable etc...
        if (m_gui) {
            // while ((m_stopIt || (m_epoch >= m_numEpochs && m_valSize == 0)) && !m_accepted) {
            while ((m_stopIt || (m_numItsPerformed >= m_numEpochs && m_valSize == 0)) && !m_accepted) {
                m_stopIt = true;
                m_stopped = true;
                //if (m_epoch >= m_numEpochs && m_valSize == 0) {
                if (m_numItsPerformed >= m_numEpochs && m_valSize == 0) {

                    m_controlPanel.m_startStop.setEnabled(false);
                } else {
                    m_controlPanel.m_startStop.setEnabled(true);
                }
                m_controlPanel.m_startStop.setText("Start");
                m_controlPanel.m_startStop.setActionCommand("Start");
                m_controlPanel.m_changeEpochs.setEnabled(true);
                m_controlPanel.m_changeLearning.setEnabled(true);
                m_controlPanel.m_changeMomentum.setEnabled(true);

                blocker(true);
                if (m_numeric) {
                    setEndsToLinear();
                }
            }
            m_controlPanel.m_changeEpochs.setEnabled(false);
            m_controlPanel.m_changeLearning.setEnabled(false);
            m_controlPanel.m_changeMomentum.setEnabled(false);

            m_stopped = false;
            // if the network has been accepted stop the training loop
            if (m_accepted) {
                return false;
            }
        }
        if (m_accepted) {
            return false;
        }
        // if (m_epoch < m_numEpochs) {
        if (m_numItsPerformed < m_numEpochs) {
            return true; // We can keep iterating
        } else {
            return false;
        }
    }

    /**
     * Signal end of iterating, useful for any house-keeping/cleanup
     *
     * @exception Exception if cleanup fails
     */
    @Override
    public void done() throws Exception {

        if (m_gui) {
            m_win.dispose();
            m_controlPanel = null;
            m_nodePanel = null;
        }

        if (!getResume()) {
            if (!m_useDefaultModel) {
                m_instances = new Instances(m_instances, 0);
            }

            m_currentInstance = null;
            valSet = null;
            originalFormatData = null;
        }
    }

    /**
     * Tool tip text for resume property
     *
     * @return the tool tip text for the finalize property
     */
    public String resumeTipText() {
        return "Set whether classifier can continue training after performing the"
                + "requested number of iterations. \n\tNote that setting this to true will "
                + "retain certain data structures which can increase the \n\t" + "size of the model.";
    }

    /**
     * If called with argument true, then the next time done() is called the model is effectively
     * "frozen" and no further iterations can be performed
     *
     * @param resume true if the model is to be finalized after performing iterations
     */
    public void setResume(boolean resume) {
        m_resume = resume;
    }

    /**
     * Returns true if the model is to be finalized (or has been finalized) after
     * training.
     *
     * @return the current value of finalize
     */
    public boolean getResume() {
        return m_resume;
    }

    /**
     * Call this function to build and train a neural network for the training
     * data provided.
     * 
     * @param i The training data.
     * @throws Exception if can't build classification properly.
     */
    @Override
    public void buildClassifier(Instances i) throws Exception {

        m_instances = null;

        // Initialize classifier
        initializeClassifier(i);

        // For the given number of iterations
        while (next()) {
        }

        // Clean up
        done();
    }

    /**
     * Call this function to predict the class of an instance once a
     * classification model has been built with the buildClassifier call.
     * 
     * @param i The instance to classify.
     * @return A double array filled with the probabilities of each class type.
     * @throws Exception if can't classify instance.
     */
    @Override
    public double[] distributionForInstance(Instance i) throws Exception {

        // default model?
        if (m_useDefaultModel) {
            return m_ZeroR.distributionForInstance(i);
        }

        if (m_useNomToBin) {
            m_nominalToBinaryFilter.input(i);
            m_currentInstance = m_nominalToBinaryFilter.output();
        } else {
            m_currentInstance = i;
        }

        // Make a copy of the instance so that it isn't modified
        m_currentInstance = (Instance) m_currentInstance.copy();

        if (m_normalizeAttributes) {
            double[] instance = new double[m_currentInstance.numAttributes()];
            for (int noa = 0; noa < m_instances.numAttributes(); noa++) {
                if (noa != m_instances.classIndex()) {
                    if (m_attributeRanges[noa] != 0) {
                        instance[noa] = (m_currentInstance.value(noa) - m_attributeBases[noa])
                                / m_attributeRanges[noa];
                    } else {
                        instance[noa] = m_currentInstance.value(noa) - m_attributeBases[noa];
                    }
                } else {
                    instance[noa] = m_currentInstance.value(noa);
                }
            }
            m_currentInstance = new DenseInstance(m_currentInstance.weight(), instance);
            m_currentInstance.setDataset(m_instances);
        }
        resetNetwork();

        // since all the output values are needed.
        // They are calculated manually here and the values collected.
        double[] theArray = new double[m_numClasses];
        for (int noa = 0; noa < m_numClasses; noa++) {
            theArray[noa] = m_outputs[noa].outputValue(true);
        }
        if (m_instances.classAttribute().isNumeric()) {
            return theArray;
        }

        // now normalize the array
        double count = 0;
        for (int noa = 0; noa < m_numClasses; noa++) {
            count += theArray[noa];
        }
        if (count <= 0) {
            return m_ZeroR.distributionForInstance(i);
        }
        for (int noa = 0; noa < m_numClasses; noa++) {
            theArray[noa] /= count;
        }
        return theArray;
    }

    /**
     * Returns an enumeration describing the available options.
     * 
     * @return an enumeration of all the available options.
     */
    @Override
    public Enumeration<Option> listOptions() {

        Vector<Option> newVector = new Vector<Option>(14);

        newVector.addElement(new Option("\tLearning rate for the backpropagation algorithm.\n"
                + "\t(Value should be between 0 - 1, Default = 0.3).", "L", 1, "-L <learning rate>"));
        newVector.addElement(new Option("\tMomentum rate for the backpropagation algorithm.\n"
                + "\t(Value should be between 0 - 1, Default = 0.2).", "M", 1, "-M <momentum>"));
        newVector.addElement(new Option("\tNumber of epochs to train through.\n" + "\t(Default = 500).", "N", 1,
                "-N <number of epochs>"));
        newVector.addElement(new Option(
                "\tPercentage size of validation set to use to terminate\n"
                        + "\ttraining (if this is non zero it can preempt num of epochs.\n"
                        + "\t(Value should be between 0 - 100, Default = 0).",
                "V", 1, "-V <percentage size of validation set>"));
        newVector.addElement(new Option("\tThe value used to seed the random number generator\n"
                + "\t(Value should be >= 0 and and a long, Default = 0).", "S", 1, "-S <seed>"));
        newVector.addElement(new Option(
                "\tThe number of consecutive increases of error allowed for validation\n"
                        + "\ttesting before training terminates.\n" + "\t(Value should be > 0, Default = 20).",
                "E", 1, "-E <threshold for number of consecutive errors>"));
        newVector.addElement(
                new Option("\tGUI will be opened.\n" + "\t(Use this to bring up a GUI).", "G", 0, "-G"));
        newVector.addElement(new Option("\tAutocreation of the network connections will NOT be done.\n"
                + "\t(This will be ignored if -G is NOT set)", "A", 0, "-A"));
        newVector.addElement(new Option("\tA NominalToBinary filter will NOT automatically be used.\n"
                + "\t(Set this to not use a NominalToBinary filter).", "B", 0, "-B"));
        newVector.addElement(new Option(
                "\tThe hidden layers to be created for the network.\n"
                        + "\t(Value should be a list of comma separated Natural \n"
                        + "\tnumbers or the letters 'a' = (attribs + classes) / 2, \n"
                        + "\t'i' = attribs, 'o' = classes, 't' = attribs .+ classes)\n"
                        + "\tfor wildcard values, Default = a).",
                "H", 1, "-H <comma separated numbers for nodes on each layer>"));
        newVector.addElement(new Option("\tNormalizing a numeric class will NOT be done.\n"
                + "\t(Set this to not normalize the class if it's numeric).", "C", 0, "-C"));
        newVector.addElement(new Option("\tNormalizing the attributes will NOT be done.\n"
                + "\t(Set this to not normalize the attributes).", "I", 0, "-I"));
        newVector.addElement(new Option(
                "\tReseting the network will NOT be allowed.\n" + "\t(Set this to not allow the network to reset).",
                "R", 0, "-R"));
        newVector.addElement(new Option(
                "\tLearning rate decay will occur.\n" + "\t(Set this to cause the learning rate to decay).", "D", 0,
                "-D"));
        newVector.addElement(new Option("\t" + resumeTipText() + "\n", "resume", 0, "-resume"));

        newVector.addAll(Collections.list(super.listOptions()));

        return newVector.elements();
    }

    /**
     * Parses a given list of options.
     * <p/>
     * 
     * <!-- options-start --> Valid options are:
     * <p/>
     * 
     * <pre>
     * -L &lt;learning rate&gt;
     *  Learning rate for the backpropagation algorithm.
     *  (Value should be between 0 - 1, Default = 0.3).
     * </pre>
     * 
     * <pre>
     * -M &lt;momentum&gt;
     *  Momentum rate for the backpropagation algorithm.
     *  (Value should be between 0 - 1, Default = 0.2).
     * </pre>
     * 
     * <pre>
     * -N &lt;number of epochs&gt;
     *  Number of epochs to train through.
     *  (Default = 500).
     * </pre>
     * 
     * <pre>
     * -V &lt;percentage size of validation set&gt;
     *  Percentage size of validation set to use to terminate
     *  training (if this is non zero it can pre-empt num of epochs.
     *  (Value should be between 0 - 100, Default = 0).
     * </pre>
     * 
     * <pre>
     * -S &lt;seed&gt;
     *  The value used to seed the random number generator
     *  (Value should be &gt;= 0 and and a long, Default = 0).
     * </pre>
     * 
     * <pre>
     * -E &lt;threshold for number of consecutive errors&gt;
     *  The number of consecutive increases of error allowed for validation
     *  testing before training terminates.
     *  (Value should be &gt; 0, Default = 20).
     * </pre>
     * 
     * <pre>
     * -G
     *  GUI will be opened.
     *  (Use this to bring up a GUI).
     * </pre>
     * 
     * <pre>
     * -A
     *  Autocreation of the network connections will NOT be done.
     *  (This will be ignored if -G is NOT set)
     * </pre>
     * 
     * <pre>
     * -B
     *  A NominalToBinary filter will NOT automatically be used.
     *  (Set this to not use a NominalToBinary filter).
     * </pre>
     * 
     * <pre>
     * -H &lt;comma separated numbers for nodes on each layer&gt;
     *  The hidden layers to be created for the network.
     *  (Value should be a list of comma separated Natural 
     *  numbers or the letters 'a' = (attribs + classes) / 2, 
     *  'i' = attribs, 'o' = classes, 't' = attribs .+ classes)
     *  for wildcard values, Default = a).
     * </pre>
     * 
     * <pre>
     * -C
     *  Normalizing a numeric class will NOT be done.
     *  (Set this to not normalize the class if it's numeric).
     * </pre>
     * 
     * <pre>
     * -I
     *  Normalizing the attributes will NOT be done.
     *  (Set this to not normalize the attributes).
     * </pre>
     * 
     * <pre>
     * -R
     *  Resetting the network will NOT be allowed.
     *  (Set this to not allow the network to reset).
     * </pre>
     * 
     * <pre>
     * -D
     *  Learning rate decay will occur.
     *  (Set this to cause the learning rate to decay).
     * </pre>
     * 
     * <!-- options-end -->
     * 
     * @param options the list of options as an array of strings
     * @throws Exception if an option is not supported
     */
    @Override
    public void setOptions(String[] options) throws Exception {
        // the defaults can be found here!!!!
        String learningString = Utils.getOption('L', options);
        if (learningString.length() != 0) {
            setLearningRate((new Double(learningString)).doubleValue());
        } else {
            setLearningRate(0.3);
        }
        String momentumString = Utils.getOption('M', options);
        if (momentumString.length() != 0) {
            setMomentum((new Double(momentumString)).doubleValue());
        } else {
            setMomentum(0.2);
        }
        String epochsString = Utils.getOption('N', options);
        if (epochsString.length() != 0) {
            setTrainingTime(Integer.parseInt(epochsString));
        } else {
            setTrainingTime(500);
        }
        String valSizeString = Utils.getOption('V', options);
        if (valSizeString.length() != 0) {
            setValidationSetSize(Integer.parseInt(valSizeString));
        } else {
            setValidationSetSize(0);
        }
        String seedString = Utils.getOption('S', options);
        if (seedString.length() != 0) {
            setSeed(Integer.parseInt(seedString));
        } else {
            setSeed(0);
        }
        String thresholdString = Utils.getOption('E', options);
        if (thresholdString.length() != 0) {
            setValidationThreshold(Integer.parseInt(thresholdString));
        } else {
            setValidationThreshold(20);
        }
        String hiddenLayers = Utils.getOption('H', options);
        if (hiddenLayers.length() != 0) {
            setHiddenLayers(hiddenLayers);
        } else {
            setHiddenLayers("a");
        }
        if (Utils.getFlag('G', options)) {
            setGUI(true);
        } else {
            setGUI(false);
        } // small note. since the gui is the only option that can change the other
          // options this should be set first to allow the other options to set
          // properly
        if (Utils.getFlag('A', options)) {
            setAutoBuild(false);
        } else {
            setAutoBuild(true);
        }
        if (Utils.getFlag('B', options)) {
            setNominalToBinaryFilter(false);
        } else {
            setNominalToBinaryFilter(true);
        }
        if (Utils.getFlag('C', options)) {
            setNormalizeNumericClass(false);
        } else {
            setNormalizeNumericClass(true);
        }
        if (Utils.getFlag('I', options)) {
            setNormalizeAttributes(false);
        } else {
            setNormalizeAttributes(true);
        }
        if (Utils.getFlag('R', options)) {
            setReset(false);
        } else {
            setReset(true);
        }
        if (Utils.getFlag('D', options)) {
            setDecay(true);
        } else {
            setDecay(false);
        }

        setResume(Utils.getFlag("resume", options));

        super.setOptions(options);

        Utils.checkForRemainingOptions(options);
    }

    /**
     * Gets the current settings of NeuralNet.
     * 
     * @return an array of strings suitable for passing to setOptions()
     */
    @Override
    public String[] getOptions() {

        Vector<String> options = new Vector<String>();

        options.add("-L");
        options.add("" + getLearningRate());
        options.add("-M");
        options.add("" + getMomentum());
        options.add("-N");
        options.add("" + getTrainingTime());
        options.add("-V");
        options.add("" + getValidationSetSize());
        options.add("-S");
        options.add("" + getSeed());
        options.add("-E");
        options.add("" + getValidationThreshold());
        options.add("-H");
        options.add(getHiddenLayers());
        if (getGUI()) {
            options.add("-G");
        }
        if (!getAutoBuild()) {
            options.add("-A");
        }
        if (!getNominalToBinaryFilter()) {
            options.add("-B");
        }
        if (!getNormalizeNumericClass()) {
            options.add("-C");
        }
        if (!getNormalizeAttributes()) {
            options.add("-I");
        }
        if (!getReset()) {
            options.add("-R");
        }
        if (getDecay()) {
            options.add("-D");
        }
        if (getResume()) {
            options.add("-resume");
        }

        Collections.addAll(options, super.getOptions());

        return options.toArray(new String[0]);
    }

    /**
     * @return string describing the model.
     */
    @Override
    public String toString() {
        // only ZeroR model?
        if (m_useDefaultModel) {
            StringBuffer buf = new StringBuffer();
            buf.append(this.getClass().getName().replaceAll(".*\\.", "") + "\n");
            buf.append(this.getClass().getName().replaceAll(".*\\.", "").replaceAll(".", "=") + "\n\n");
            buf.append("Warning: No model could be built, hence ZeroR model is used:\n\n");
            buf.append(m_ZeroR.toString());
            return buf.toString();
        }

        StringBuffer model = new StringBuffer(m_neuralNodes.length * 100);
        // just a rough size guess
        NeuralNode con;
        double[] weights;
        NeuralConnection[] inputs;
        for (NeuralConnection m_neuralNode : m_neuralNodes) {
            con = (NeuralNode) m_neuralNode; // this would need a change
                                             // for items other than nodes!!!
            weights = con.getWeights();
            inputs = con.getInputs();
            if (con.getMethod() instanceof SigmoidUnit) {
                model.append("Sigmoid ");
            } else if (con.getMethod() instanceof LinearUnit) {
                model.append("Linear ");
            }
            model.append("Node " + con.getId() + "\n    Inputs    Weights\n");
            model.append("    Threshold    " + weights[0] + "\n");
            for (int nob = 1; nob < con.getNumInputs() + 1; nob++) {
                if ((inputs[nob - 1].getType() & NeuralConnection.PURE_INPUT) == NeuralConnection.PURE_INPUT) {
                    model.append(
                            "    Attrib " + m_instances.attribute(((NeuralEnd) inputs[nob - 1]).getLink()).name()
                                    + "    " + weights[nob] + "\n");
                } else {
                    model.append("    Node " + inputs[nob - 1].getId() + "    " + weights[nob] + "\n");
                }
            }
        }
        // now put in the ends
        for (NeuralEnd m_output : m_outputs) {
            inputs = m_output.getInputs();
            model.append("Class " + m_instances.classAttribute().value(m_output.getLink()) + "\n    Input\n");
            for (int nob = 0; nob < m_output.getNumInputs(); nob++) {
                if ((inputs[nob].getType() & NeuralConnection.PURE_INPUT) == NeuralConnection.PURE_INPUT) {
                    model.append("    Attrib " + m_instances.attribute(((NeuralEnd) inputs[nob]).getLink()).name()
                            + "\n");
                } else {
                    model.append("    Node " + inputs[nob].getId() + "\n");
                }
            }
        }
        return model.toString();
    }

    /**
     * This will return a string describing the classifier.
     * 
     * @return The string.
     */
    public String globalInfo() {
        return "A classifier that uses backpropagation to learn a multi-layer perceptron to classify instances.\n"
                + "The network can be built by hand or or set up using a simple heuristic. "
                + "The network parameters can also be monitored and modified during training time. "
                + "The nodes in this network are all sigmoid (except for when the class "
                + "is numeric, in which case the output nodes become unthresholded " + "linear units).";
    }

    /**
     * @return a string to describe the learning rate option.
     */
    public String learningRateTipText() {
        return "The learning rate for weight updates.";
    }

    /**
     * @return a string to describe the momentum option.
     */
    public String momentumTipText() {
        return "Momentum applied to the weight updates.";
    }

    /**
     * @return a string to describe the AutoBuild option.
     */
    public String autoBuildTipText() {
        return "Adds and connects up hidden layers in the network.";
    }

    /**
     * @return a string to describe the random seed option.
     */
    public String seedTipText() {
        return "Seed used to initialise the random number generator."
                + "Random numbers are used for setting the initial weights of the"
                + " connections between nodes, and also for shuffling the training data.";
    }

    /**
     * @return a string to describe the validation threshold option.
     */
    public String validationThresholdTipText() {
        return "Used to terminate validation testing."
                + "The value here dictates how many times in a row the validation set"
                + " error can get worse before training is terminated.";
    }

    /**
     * @return a string to describe the GUI option.
     */
    public String GUITipText() {
        return "Brings up a gui interface." + " This will allow the pausing and altering of the neural network"
                + " during training.\n\n" + "* To add a node, left click (this node will be automatically selected,"
                + " ensure no other nodes were selected).\n"
                + "* To select a node, left click on it either while no other node is"
                + " selected or while holding down the control key (this toggles selection).\n"
                + "* To connect a node, first have the start node(s) selected, then click"
                + " either the end node or on an empty space (this will create a new node"
                + " that is connected with the selected nodes). The selection status of"
                + " nodes will stay the same after the connection. (Note these are"
                + " directed connections. Also, a connection between two nodes will not"
                + " be established more than once and certain connections that are"
                + " deemed to be invalid will not be made).\n"
                + "* To remove a connection. select one of the connected node(s) in the"
                + " connection and then right click the other node (it does not matter"
                + " whether the node is the start or end: the connection will be removed" + ").\n"
                + "* To remove a node, right click it while no other nodes (including it)"
                + " are selected. (This will also remove all connections to it)\n."
                + "* To deselect a node either left click it while holding down control"
                + " or right click on empty space.\n"
                + "* The raw inputs are provided from the labels on the left.\n"
                + "* The red nodes are hidden layers.\n" + "* The orange nodes are the output nodes.\n"
                + "* The labels on the right show the class the output node represents."
                + " Note that with a numeric class the output node will automatically be"
                + " made into an unthresholded linear unit.\n\n"
                + "Alterations to the neural network can only be done while the network"
                + " is not running, This also applies to the learning rate and other"
                + " fields on the control panel.\n\n"
                + "* You can accept the network as being finished at any time.\n"
                + "* The network is automatically paused at the beginning.\n"
                + "* There is a running indication of what epoch the network is up to"
                + " and what the (rough) training error for that epoch was (or for"
                + " the validation set if that is being used). Note that this error value"
                + " is based on a network that changes as the value is computed." + " (Also, whether"
                + " the class is normalized will affect the error reported for numeric" + " classes.)\n"
                + "* Once the network is done, it will pause again and either wait to be"
                + " accepted or trained more.\n\n"
                + "Note that if the GUI is not set, the network will not require any" + " interaction.\n";
    }

    /**
     * @return a string to describe the validation size option.
     */
    public String validationSetSizeTipText() {
        return "The percentage size of the validation set."
                + "(The training will continue until it is observed that"
                + " the error on the validation set has been consistently getting"
                + " worse, or if the training time is reached).\n"
                + "If this is set to zero, no validation set will be used and instead"
                + " the network will train for the specified number of epochs.";
    }

    /**
     * @return a string to describe the learning rate option.
     */
    public String trainingTimeTipText() {
        return "The number of epochs to train through."
                + " If the validation set is non-zero then it can terminate the network" + " early";
    }

    /**
     * @return a string to describe the nominal to binary option.
     */
    public String nominalToBinaryFilterTipText() {
        return "This will preprocess the instances with the NominalToBinary filter."
                + " This could help improve performance if there are nominal attributes" + " in the data.";
    }

    /**
     * @return a string to describe the hidden layers in the network.
     */
    public String hiddenLayersTipText() {
        return "This defines the hidden layers of the neural network."
                + " This is a list of positive whole numbers. 1 for each hidden layer."
                + " Comma separated. To have no hidden layers put a single 0 here."
                + " This layer definition will only be used if autobuild is set. There are also wildcard"
                + " values: 'a' = (attribs + classes) / 2, 'i' = attribs, 'o' = classes"
                + " , 't' = attribs + classes.";
    }

    /**
     * @return a string to describe the nominal to binary option.
     */
    public String normalizeNumericClassTipText() {
        return "This will normalize the class if it is numeric."
                + " This can help improve performance of the network. It normalizes"
                + " the class to be between -1 and 1. Note that this is only internally"
                + ", the output will be scaled back to the original range.";
    }

    /**
     * @return a string to describe the nominal to binary option.
     */
    public String normalizeAttributesTipText() {
        return "This will normalize the attributes." + " This can help improve performance of the network."
                + " This is not reliant on the class being numeric. This will also"
                + " normalize nominal attributes (after they have been run"
                + " through the nominal to binary filter if that is in use) so that the"
                + " binary values are between -1 and 1";
    }

    /**
     * @return a string to describe the Reset option.
     */
    public String resetTipText() {
        return "This will allow the network to reset with a lower learning rate."
                + " If the network diverges from the answer, this will automatically"
                + " reset the network with a lower learning rate and begin training"
                + " again. This option is only available if the GUI is not set. Note"
                + " that if the network diverges but is not allowed to reset, it will"
                + " fail the training process and return an error message.";
    }

    /**
     * @return a string to describe the Decay option.
     */
    public String decayTipText() {
        return "This will cause the learning rate to decrease."
                + " This will divide the starting learning rate by the epoch number to"
                + " determine what the current learning rate should be. This may help"
                + " to stop the network from diverging from the target output, as well"
                + " as improve general performance. Note that the decaying learning"
                + " rate will not be shown in the GUI, only the original learning rate"
                + ". If the learning rate is changed in the GUI, this is treated as the"
                + " starting learning rate.";
    }

    /**
     * Returns the revision string.
     * 
     * @return the revision
     */
    @Override
    public String getRevision() {
        return RevisionUtils.extract("$Revision$");
    }
}