001    /*
002     * Copyright (C) 2008-2010 by Holger Arndt
003     *
004     * This file is part of the Universal Java Matrix Package (UJMP).
005     * See the NOTICE file distributed with this work for additional
006     * information regarding copyright ownership and licensing.
007     *
008     * UJMP is free software; you can redistribute it and/or modify
009     * it under the terms of the GNU Lesser General Public License as
010     * published by the Free Software Foundation; either version 2
011     * of the License, or (at your option) any later version.
012     *
013     * UJMP is distributed in the hope that it will be useful,
014     * but WITHOUT ANY WARRANTY; without even the implied warranty of
015     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
016     * GNU Lesser General Public License for more details.
017     *
018     * You should have received a copy of the GNU Lesser General Public
019     * License along with UJMP; if not, write to the
020     * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
021     * Boston, MA  02110-1301  USA
022     */
023    
024    package org.ujmp.jblas.calculation;
025    
026    import org.jblas.DoubleMatrix;
027    import org.jblas.Eigen;
028    import org.ujmp.core.Matrix;
029    import org.ujmp.core.interfaces.HasColumnMajorDoubleArray1D;
030    import org.ujmp.jblas.JBlasDenseDoubleMatrix2D;
031    
032    public class Eig
033                    implements
034                    org.ujmp.core.doublematrix.calculation.general.decomposition.Eig<Matrix> {
035    
036            public static Eig INSTANCE = new Eig();
037    
038            public Matrix[] calc(Matrix source) {
039                    final DoubleMatrix matrix;
040                    if (source instanceof JBlasDenseDoubleMatrix2D) {
041                            matrix = ((JBlasDenseDoubleMatrix2D) source).getWrappedObject();
042                    } else if (source instanceof HasColumnMajorDoubleArray1D) {
043                            matrix = new JBlasDenseDoubleMatrix2D(source.getRowCount(), source
044                                            .getColumnCount(), ((HasColumnMajorDoubleArray1D) source)
045                                            .getColumnMajorDoubleArray1D()).getWrappedObject();
046                    } else {
047                            matrix = new JBlasDenseDoubleMatrix2D(source).getWrappedObject();
048                    }
049                    final DoubleMatrix[] eig = Eigen.symmetricEigenvectors(matrix);
050                    final Matrix e = new JBlasDenseDoubleMatrix2D(eig[0]);
051                    final Matrix d = new JBlasDenseDoubleMatrix2D(eig[1]);
052                    return new Matrix[] { e, d };
053            }
054    
055    }