package com.imsl.test.example.math;

import com.imsl.math.*;

/**
 * <p>
 * Computes the SVD factorization of a complex matrix.</p>
 * The singular value decomposition of a matrix is performed. The generalized
 * inverse and rank of the matrix are also computed.
 *
 * @see <a href="ComplexSVDEx1.java">Code</a>
 * @see <a href="doc-files/ComplexSVDEx1.out">Output</a>
 */
public class ComplexSVDEx1 {

    public static void main(String args[]) throws
            ComplexSVD.DidNotConvergeException {

        Complex a[][] = {
            {new Complex(1.0, 2.0), new Complex(3.0, 2.0),
                new Complex(1.0, -4.0)},
            {new Complex(3.0, -2.0), new Complex(2.0, -4.0),
                new Complex(1.0, 3.0)},
            {new Complex(4.0, 3.0), new Complex(-2.0, 1.0),
                new Complex(1.0, 4.0)},
            {new Complex(2.0, -1.0), new Complex(3.0, 0.0),
                new Complex(3.0, -1.0)},
            {new Complex(1.0, -5.0), new Complex(2.0, -5.0),
                new Complex(2.0, 2.0)},
            {new Complex(1.0, 2.0), new Complex(4.0, -2.0),
                new Complex(2.0, -3.0)}
        };

        // Compute the SVD factorization of A.
        ComplexSVD svd = new ComplexSVD(a);

        // Print U, S, V and the Moore-Penrose inverse.
        new PrintMatrix("U").print(svd.getU());
        new PrintMatrix("S").print(svd.getS());
        new PrintMatrix("V").print(svd.getV());
        new PrintMatrix("Inverse").print(svd.getInverse());

        // Find the rank of A.
        int rank = svd.getRank();
        System.out.println("rank = " + rank);
    }
}