package org.jutil.math.matrix;/** * A class of eigenvalue decompositions of a matrix. * * @path    $Source: /cvsroot/org-jutil/jutil.org/src/org/jutil/math/matrix/EigenvalueDecomposition.java,v $ * @version $Revision: 1.4 $ * @date    $Date: 2002/07/02 14:27:31 $ * @state   $State: Exp $ * @author  Marko van Dooren * @release $Name:  $ */public interface EigenvalueDecomposition {	/* The revision of this class */	public final static String CVS_REVISION ="$Revision: 1.4 $";	/**	 * Return the eigenvalue matrix of this EigenvalueDecomposition.	 */ /*@	 @ public behavior	 @	 @ post \result != null;	 @ post \result.isDiagonal();   @ post \result.getNbRows() == getNbEigenvalues();   @ post \result.isSquare();	 @ post (\forall int i; i>=1 && i <= getNbEigenvalues();	 @        \result.elementAt(i,i) == getEigenvalue(i));	 @*/	public Matrix lambda();	/**	 * Return the eigenvectors.	 */ /*@	 @ public behavior	 @	 @ post \result != null;	 @*/  public Matrix getEigenvectors();  /**   * Return the eigenvalues.	 */ /*@	 @ public behavior	 @	 @ post \result != null;	 @ post (\forall int i; i>=1 && i<=\result.size();	 @        \result.elementAt(i) != 0);	 @*/  public Column getEigenvalues();	/**	 * Return the index'th eigenvector.	 *	 * @param index	 *        The index of the requested eigenvector.	 */ /*@	 @ public behavior	 @	 @ pre index >= 1;	 @ pre index <= getNbEigenvalues();	 @	 @ post \result.equals(getEigenvectors().getColumn(index));	 @*/  public Column getEigenvector(int index);	/**	 * Return the index'th eigenvalue.	 *	 * @param index	 *        The index of the requested eigenvalue.	 */ /*@	 @ public behavior	 @	 @ pre index >= 1;	 @ pre index <= getNbEigenvalues();	 @	 @ post \result == getEigenvalues().elementAt(index);	 @*/  public double getEigenvalue(int index);  /**	 * Return the number of eigenvalues.	 */ /*@	 @ public behavior	 @	 @ post \result == getEigenvalues().size();	 @*/	public int getNbEigenvalues();}/*<copyright>Copyright (C) 1997-2002. This software is copyrighted by the people and entities mentioned after the "@author" tags above, on behalf of the JUTIL.ORG Project. The copyright is dated by the dates after the "@date" tags above. All rights reserved.This software is published under the terms of the JUTIL.ORG SoftwareLicense version 1.1 or later, a copy of which has been included withthis distribution in the LICENSE file, which can also be found athttp://org-jutil.sourceforge.net/LICENSE. This software is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the JUTIL.ORG Software License for more details.For more information, please see http://org-jutil.sourceforge.net/</copyright>*/