Eigen.java

package GeDBIT.index.algorithms;

import cern.colt.matrix.DoubleMatrix2D;
import cern.colt.matrix.impl.DenseDoubleMatrix2D;
//import cern.colt.matrix.linalg.Algebra;
import cern.colt.matrix.linalg.EigenvalueDecomposition;

public class Eigen {
    double x[][];
    DoubleMatrix2D x_matrix;
    DoubleMatrix2D eigen_matrix;
    float float_positive_result[];
    float sort_result[];

    // construction function
    public Eigen(double[][] m_x) {

	x = m_x;
	x_matrix = new DenseDoubleMatrix2D(x);
	float_positive_result = new float[x_matrix.columns()];
	sort_result = new float[x_matrix.columns()];
    }

    public int calEigen() {
	EigenvalueDecomposition eigen_cal = new EigenvalueDecomposition(
		x_matrix);
	eigen_matrix = eigen_cal.getD();
	@SuppressWarnings("unused")
	int[] result = getEigen();
	sort();
	return 0;
    }

    public int[] getEigen() {
	int[] result = new int[eigen_matrix.columns()];
	for (int i = 0; i < eigen_matrix.columns(); i++) {
	    // result[i] = eigen_matrix.get(i, i);
	    Double double_temp = eigen_matrix.get(i, i);
	    if (double_temp < 0)
		double_temp = -double_temp;
	    Float float_temp = double_temp.floatValue();

	    float_positive_result[i] = float_temp;
	    result[i] = float_temp.intValue();
	}

	return result;
    }

    public int printEigenDouble() {
	// int i = 0;
	for (int i = 0; i < eigen_matrix.columns(); i++)
	    System.out.println(eigen_matrix.get(i, i) + " ");
	System.out.println();
	return 0;
    }

    public int printEigenFloat() {
	for (int i = 0; i < eigen_matrix.columns(); i++) {
	    Double temp_double = eigen_matrix.get(i, i);
	    System.out.printf("%.3f", temp_double.floatValue());
	    // System.out.print(" ");
	    System.out.println();
	}
	System.out.println();
	return 0;
    }

    public int printEigenFloatPositive() {
	for (int i = 0; i < eigen_matrix.columns(); i++) {
	    // Double temp_double = eigen_matrix.get(i, i);
	    // if(temp_double<0)
	    // temp_double = -temp_double;
	    // System.out.printf("%.3f\n", temp_double.floatValue());
	    // float_positive_result[i] = temp_double.floatValue();
	    System.out.printf("%.3f\n", float_positive_result[i]);
	}
	return 0;
    }

    public int sort() {
	int n = eigen_matrix.columns();
	float temp = 0;
	for (int i = 0; i < n; i++)
	    sort_result[i] = float_positive_result[i];
	for (int i = 0; i < n; i++)
	    for (int j = i + 1; j < n; j++)
		if (sort_result[i] < sort_result[j]) {
		    temp = sort_result[i];
		    sort_result[i] = sort_result[j];
		    sort_result[j] = temp;
		}

	// for(int i=0; i<n; i++)
	// System.out.printf("%.3f\n", sort_result[i]);
	return 0;
    }

    public int calPivotNumber() {
	int n = eigen_matrix.columns();
	double maxratio = 0.0;
	int numPivot = 0;
	for (int i = 1; i < n - 1; i++) {
	    double ratio = sort_result[i] / sort_result[i + 1];
	    if (ratio > maxratio) {
		maxratio = ratio;
		numPivot = i;
	    }
	}
	return numPivot + 1;
    }

    public int printBiggestEigen(int n) {
	// sort();
	for (int i = 0; i < n; i++)
	    System.out.printf("%.3f\n", sort_result[i]);
	// System.out.printf("%.3f\n", float_positive_result[i]);
	return 0;
    }

    public int printSortResult() {
	int n = eigen_matrix.columns();
	System.out.println("Eigen result::::::");
	for (int i = 0; i < n; i++)
	    System.out.println(sort_result[i]);
	System.out.println("::::::::::::::::");
	return 0;
    }

}