algorithmpca.java

包含了模式识别中常用的一些分类器设计算法

/**
 * @(#) AlgorithmPCA.java   v6.0 05/23/2005
 * last edited Ryan Irwin 
 * document created  02/09/03
 *
 * Defines the operation of the PCA Class-Independent Algorithm
 *
 */


// import java packages
//
import java.awt.*;
import java.util.*;

/**
 * Operation of the PCA Class-Independent Algorithm
 */
public class AlgorithmPCA extends Algorithm
{
    
    //-----------------------------------------------------------------
    //
    // instance data members
    //
    //-----------------------------------------------------------------
    
    // vector of support region points
    //
    Matrix trans_matrix_d = new Matrix();
    Matrix cov_matrix_d = new Matrix();
    Vector<MyPoint> support_vectors_d = new Vector<MyPoint>();
    Vector<MyPoint> decision_regions_d = new Vector<MyPoint>();
    int output_canvas_d[][];
    

    //-----------------------------------------------------------------
    //
    // public class methods
    //
    //------------------------------------------------------------------

    /**
     * Overrides the initialize() method in the base class.  Initializes
     * member data and prepares for execution of first step.  This method
     * "resets" the algorithm.
     *
     * @return true
     */
    public boolean initialize()
    {
	// Debug
	//
	// System.out.println(algo_id + ": initialize()");
	
	trans_matrix_d = new Matrix();
	cov_matrix_d = new Matrix();
	support_vectors_d = new Vector<MyPoint>();
	point_means_d = new Vector<MyPoint>();
	decision_regions_d = new Vector<MyPoint>();
	step_count = 3;
	algo_id = "AlgorithmPCA";
	
	// add the process description for the PCA algorithm
	//
	if (description_d.size() == 0)
        {
	    String str = new String("   0. Initialize the original data.");
	    description_d.addElement(str);
	    
	    str = new String("   1. Displaying the original data.");
	    description_d.addElement(str);
	    
	    str = new String("   2. Computing the support regions.");
	    description_d.addElement(str);
	    
	    str = new String("   3. Computing the decision regions based on the class independent principal component analysis algorithm.");
	    description_d.addElement(str);
	}
	    
	// append message to process box
	//
	pro_box_d.appendMessage("Class Independent Principal" 
				+ " Component Analysis:" + "\n");

	// set the data points for this algorithm
	//
	//	set1_d = (Vector)data_points_d.dset1.clone();
	//	set2_d = (Vector)data_points_d.dset2.clone();
	//	set3_d = (Vector)data_points_d.dset3.clone();
	//	set4_d = (Vector)data_points_d.dset4.clone();
	//
	set1_d = data_points_d.dset1;
	set2_d = data_points_d.dset2;
	set3_d = data_points_d.dset3;
	set4_d = data_points_d.dset4;
	
	// set the step index
	//
	step_index_d = 0;
	
	// append message to process box
	//
	pro_box_d.appendMessage((String)description_d.get(step_index_d));
	
	// exit gracefully
	//
	return true;
    }
    
    /**
     * Implementation of the run function from the Runnable interface.
     * Determines what the current step is and calls the appropriate method.
     */
    public void run()
    {
	// Debug
	//
	// System.out.println(algo_id + ": run()");
	
	if (step_index_d == 1)
	{
	    disableControl();
	    step1();
	    enableControl();
	}
	    
        else if (step_index_d == 2)
	{
	    disableControl();
	    step2(); 
	    enableControl();
	}
	
	else if (step_index_d == 3)
        {
	    disableControl();
	    step3();
	    pro_box_d.appendMessage("   Algorithm Complete");
	    enableControl(); 
	}
	
	// exit gracefully
	//
	return;
    }
    
    /**
     *
     * step one of the algorithm. Scales the display to fit the plot.
     *
     * @return true
     */
    boolean step1()
    {
	// Debug
	//
	// System.out.println(algo_id + ": step1()");
	
	pro_box_d.setProgressMin(0);
	pro_box_d.setProgressMax(1);
	pro_box_d.setProgressCurr(0);
	
	scaleToFitData();
	
	// Display original data
	//
	output_panel_d.addOutput(set1_d, Classify.PTYPE_INPUT, 
				 data_points_d.color_dset1);
	output_panel_d.addOutput(set2_d, Classify.PTYPE_INPUT,
				 data_points_d.color_dset2);
	output_panel_d.addOutput(set3_d, Classify.PTYPE_INPUT,
				 data_points_d.color_dset3);
	output_panel_d.addOutput(set4_d, Classify.PTYPE_INPUT, 
				 data_points_d.color_dset4);
	
	// step 1 completed
	//
	pro_box_d.setProgressCurr(1);
	output_panel_d.repaint();
	
	// exit gracefully
	//
	return true;
    }

    /**
     *
     * step two of the algorithm. Finds the PCA for the given data
     *
     * @return true
     */
    boolean step2()
    {
	// Debug
	//System.out.println(algo_id + ": step2()");
	
	
	pro_box_d.setProgressMin(0);
	pro_box_d.setProgressMax(20);
	pro_box_d.setProgressCurr(0);
	
	// append message to process box
	//
	transformPCA();
	printMatrices();
	computeMeans();
	
	// display means
	//
	output_panel_d.addOutput(point_means_d, Classify.PTYPE_OUTPUT_LARGE, 
				 Color.black);
	
	// display support vectors
	//
	output_panel_d.addOutput(support_vectors_d, Classify.PTYPE_INPUT, 
				 Color.cyan);
	
	// display support vectors
	//
	pro_box_d.setProgressCurr(20);
	output_panel_d.repaint();
	
	// exit gracefully
	//
	return true;
    }

    /**
     *
     * step three of the algorithm. Computes the decision regions
     *
     * @return true
     */
    boolean step3()
    {
	// Debug
	//
	// System.out.println(algo_id + ": step3()");
	
	pro_box_d.setProgressMin(0);
	pro_box_d.setProgressMax(20);
	pro_box_d.setProgressCurr(0);
	
	// compute the decision regisions
	//
	computeDecisionRegions();
	    
	// compute errors
	//
	computeErrors();
	
	// display support vectors
	//
	// display support vectors
	//
	output_panel_d.addOutput(decision_regions_d, Classify.PTYPE_INPUT, 
				 new Color(255, 200, 0));
	
	output_panel_d.repaint();
	
	// exit gracefully
	//
	return true;
    }
    
    /**
     * 
     * transforms a given set of points to a new space
     * using the class independent principal component analysis algorithm
     *
     */
    public void transformPCA()
    {
	// Debug
	// 
	// System.out.println(algo_id + ": transformPCA()");
	    
	// declare local variables
	//
	int size = 0;
	int xsize = 0;
	int ysize = 0;
	    
	// declare variables to compute the global mean
	//
	double xval = 0.0;
	double yval = 0.0;
	double xmean = 0.0;
	double ymean = 0.0;
	    
	// declare the covariance object
	//
	Covariance cov = new Covariance();
	    
	// declare an eigen object
	//
	// Since Eigen is a class of static member functions 
	// it is not correct to instantiate it - Phil T. 6-23-03 
	//Eigen eigen = new Eigen();
	
	// declare the covariance matrix
	//
	Matrix covariance = new Matrix();
	covariance.row = covariance.col = 2;
	covariance.Elem = new double[2][2];
	    
	// declare arrays for the eigenvalues
	//
	double eigVal[] = null;
	    
	// declare an array to store the eigen vectors
	//
	double eigVec[] = new double[2];
	    
	// declare matrix objects
	//
	Matrix T = new Matrix();
	Matrix M = new Matrix();
	Matrix W = new Matrix();
	    
	// allocate memory for the matrix elements
	//
	T.Elem = new double[2][2];
	M.Elem = new double[2][2];
	W.Elem = new double[2][2];
	    
	// declare arrays to store the samples
	//
	double x[] = null;
	double y[] = null;
	    
	// declare the maximum size of all data sets together
	//
	int maxsize = set1_d.size() + set2_d.size() 
	            + set3_d.size() + set4_d.size();
	    
	// initialize arrays to store the samples
	//
	x = new double[maxsize];
	y = new double[maxsize];
	    
	// get the samples from the first data set
	//
	size = set1_d.size();
	    
	// set up the initial random vectors i.e., the vectors of
	// X and Y coordinate points form the display
	//
	for (int i = 0; i < size; i++)
        {
	    MyPoint p = (MyPoint)set1_d.elementAt(i);
	    xval += p.x;
	    yval += p.y;
	    x[xsize++] = p.x;
	    y[ysize++] = p.y;
	}
	
	// get the samples from the second data set
	//
	size = set2_d.size();
	
	// set up the initial random vectors i.e., the vectors of
	// X and Y coordinate points form the display
	//
	for (int i = 0; i < size; i++)
        {
	    MyPoint p = (MyPoint)set2_d.elementAt(i);
	    xval += p.x;
	    yval += p.y;
	    x[xsize++] = p.x;
	    y[ysize++] = p.y;
	}
	
	// get the samples from the third data set
	//
	size = set3_d.size();
	
	// set up the initial random vectors i.e., the vectors of
	// X and Y coordinate points form the display
	//
	for (int i = 0; i < size; i++)
        {
	    MyPoint p = (MyPoint)set3_d.elementAt(i);
	    xval += p.x;
	    yval += p.y;
	    x[xsize++] = p.x;
	    y[ysize++] = p.y;
	}
	
	// get the samples from the first data set
	//
	size = set4_d.size();
	
	// set up the initial random vectors i.e., the vectors of
	// X and Y coordinate points form the display
	//
	for (int i = 0; i < size; i++)
        {
	    MyPoint p = (MyPoint)set4_d.elementAt(i);
	    xval += p.x;
	    yval += p.y;
	    x[xsize++] = p.x;
	    y[ysize++] = p.y;
	}
	
	if (maxsize > 0)
	{
	    
	    // initialize the transformation matrix dimensions
	    //
	    W.row = 2;
	    W.col = 2;
	    
	    // reset the matrices
	    //
	    W.resetMatrix();
	    
	    // compute the covariance matrix of the first data set
	    //
	    covariance.Elem = cov.computeCovariance(x, y);
	    cov_matrix_d = covariance;
	    
	    // initialize the matrix needed to compute the eigenvalues
	    //
	    T.initMatrix(covariance.Elem, 2, 2);
	    
	    // make a copy of the original matrix
	    //
	    M.copyMatrix(T);
	    
	    // compute the eigen values
	    //
	    // Changed eigen to Eigen since member function is static -
	    // Phil T. 6-23-03
	    eigVal = Eigen.compEigenVal(T);
	    
	    // compute the eigen vectors
	    //
	    for (int i = 0; i < 2; i++)
	    {
		// Changed eigen to Eigen since member function is static - 
		// Phil T. 6-23-03
		Eigen.calcEigVec(M, eigVal[i], eigVec);
		for (int j = 0; j < 2; j++)
		{
		    W.Elem[j][i] = eigVec[j] / Math.sqrt(eigVal[i]);
		}
	    }
	    
	    // save the transformation matrix 
	    //
	    trans_matrix_d = W;
	}
	
	// compute the global mean of the data sets
	//
	xmean = xval / xsize;
	ymean = yval / ysize;
	
	// determine points for the support regions
	//
	double val[][] = new double[2][1];
	
	Matrix invT = new Matrix();
	Matrix supp = new Matrix();
	Matrix temp = new Matrix();
	
	// set up the angle with which to rotate the axis
	//
	double theta = 0.0;
	double alpha = cov_matrix_d.Elem[0][0] - cov_matrix_d.Elem[1][1];
	double beta = -2 * cov_matrix_d.Elem[0][1];
	    
	if (eigVal[0] > eigVal[1])