package org.jutil.math.matrix;/** * This is a class of N-dimensional matrices * * The name Matrix has been reserved for 2D matrices since they are * use more frequently than a general N-dimensional matrix. * * Since java has no generic classes, a matrix contains double values. * * @path    $Source: /cvsroot/org-jutil/jutil.org/src/org/jutil/math/matrix/NMatrix.java,v $ * @version $Revision: 1.2 $ * @date    $Date: 2002/05/20 15:01:37 $ * @state   $State: Exp $ * @author  Marko van Dooren * @release $Name:  $ */public abstract class NMatrix {	/* The revision of this class */	public final static String CVS_REVISION ="$Revision: 1.2 $"; /*@   @ public invariant getDimensions().length == getNbDimensions();   @ public invariant (\forall int i; i>=0 && i<getNbDimensions();   @                     getDimensions()[i] > 0);   @*/  /**   * Return the number of dimensions of this matrix.   */  public abstract int getNbDimensions();  /**   * Return the dimensions of this matrix   */ /*@   @ post \result.length == getNbDimensions();   @*/  public abstract int[] getDimensions();  /**   * Return the element at the given index.   *   * @param index   *        The index of the requested element.   */ /*@   @ pre validIndex(index);   @*/  public abstract double elementAt(int[] index);  /**   * Set the element at the given index to the given value.   *   * @param index   *        The index of the element to be changed.   * @param value   *        The new value for the element at index <index>.   */ /*@   @ pre validIndex(index);   @   @ post elementAt(index) == value;   @*/  public abstract void setElementAt(int[] index, double value);  /**   * Check whether or not the given index is a valid index for this matrix.   *   * @param index   *        The index to be verified.   */ /*@   @ post \result == (index != null) &&   @                 (index.length == getNbDimensions()) &&   @                 (\forall int i; i>=0 && i<getNbDimensions();   @                   (index[i] > 0) && (index[i] <= getDimensions()[i]));   @*/  public boolean validIndex(int[] index) {    if ((index == null) || (index.length != getNbDimensions())){      return false;    }    int[] dims = getDimensions();    for(int i=0; i<index.length; i++) {      if((index[i] <= 0) || index[i] > dims[i]) {        return false;      }    }    return true;  }}/*<copyright>Copyright (C) 1997-2001. 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://www.jutil.org/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://jutil.org/</copyright>*/