Examples with EigenDecomposition org.apache.ignite.ml.math.decompositions.EigenDecomposition used on opensource projects

Example 1 with EigenDecomposition

use of org.apache.ignite.ml.math.decompositions.EigenDecomposition in project ignite by apache.

the class EigenDecompositionExample method main.

/**
     * Executes example.
     *
     * @param args Command line arguments, none required.
     */
public static void main(String[] args) {
    System.out.println(">>> Eigen decomposition example started.");
    // Let's compute EigenDecomposition for some square (n x n) matrix m with real eigenvalues:
    // m = v d v^{-1}, where d is diagonal matrix having eigenvalues of m on diagonal
    // and v is matrix where i-th column is eigenvector for i-th eigenvalue (i from 0 to n - 1)
    DenseLocalOnHeapMatrix m = new DenseLocalOnHeapMatrix(new double[][] { { 1.0d, 0.0d, 0.0d, 0.0d }, { 0.0d, 1.0d, 0.0d, 0.0d }, { 0.0d, 0.0d, 2.0d, 0.0d }, { 1.0d, 1.0d, 0.0d, 2.0d } });
    System.out.println("\n>>> Matrix m for decomposition: ");
    Tracer.showAscii(m);
    EigenDecomposition dec = new EigenDecomposition(m);
    System.out.println("\n>>> Made decomposition.");
    System.out.println(">>> Matrix getV is ");
    Tracer.showAscii(dec.getV());
    System.out.println(">>> Matrix getD is ");
    Tracer.showAscii(dec.getD());
    // From this decomposition we, for example, can easily compute determinant of matrix m
    // det (m) = det (v d v^{-1}) =
    // det(v) det (d) det(v^{-1}) =
    // det(v) det(v)^{-1} det(d) =
    // det (d) =
    // product of diagonal elements of d =
    // product of eigenvalues
    double det = dec.getRealEigenValues().foldMap(Functions.MULT, Functions.IDENTITY, 1.0);
    System.out.println("\n>>> Determinant is " + det);
    System.out.println("\n>>> Eigen decomposition example completed.");
}