/*
 * Copyright (C) 2008-2015 by Holger Arndt
 *
 * This file is part of the Universal Java Matrix Package (UJMP).
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership and licensing.
 *
 * UJMP is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * UJMP is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with UJMP; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

package org.ujmp.ejml.calculation;

import org.ejml.data.DenseMatrix64F;
import org.ejml.factory.DecompositionFactory;
import org.ejml.interfaces.decomposition.SingularValueDecomposition;
import org.ujmp.core.Matrix;
import org.ujmp.ejml.EJMLDenseDoubleMatrix2D;

public class SVD implements org.ujmp.core.doublematrix.calculation.general.decomposition.SVD<Matrix> {

	public static SVD INSTANCE = new SVD();

	public Matrix[] calc(Matrix source) {
		SingularValueDecomposition<DenseMatrix64F> svd = DecompositionFactory.svd((int) source.getRowCount(),
				(int) source.getColumnCount(), true, true, false);

		if (source instanceof EJMLDenseDoubleMatrix2D) {
			svd.decompose(((EJMLDenseDoubleMatrix2D) source).getWrappedObject());
		} else {
			svd.decompose(new EJMLDenseDoubleMatrix2D(source).getWrappedObject());
		}
		Matrix u = new EJMLDenseDoubleMatrix2D(svd.getU(null, false));
		Matrix v = new EJMLDenseDoubleMatrix2D(svd.getV(null, false));
		Matrix s = new EJMLDenseDoubleMatrix2D(svd.getW(null));
		return new Matrix[] { u, s, v };
	}

}
