SquareMatrix.java

package sim.util.mantissa.linalg;

import java.io.Serializable;

/** This class factor all services common to square matrices of linear algebra.

 * <p>This class is the base class of all square matrix
 * implementations. It extends the {@link Matrix} class with methods
 * specific to square matrices.</p>

 <p>This file is from the "Mantissa" Java software package found at
 <a href="http://www.spaceroots.org/software/mantissa/index.html">
 http://www.spaceroots.org/software/mantissa/index.html</a>.  The license is included
 at the end of the source file.

 * @version $Id: SquareMatrix.java,v 1.1 2007-05-30 14:01:30 feijai Exp $
 * @author L. Maisonobe

 */

public abstract class SquareMatrix
    extends Matrix
    implements Serializable, Cloneable {
    /** Simple constructor.
     * Build a matrix with null elements.
     * @param order order of the matrix
     */
    protected SquareMatrix(int order) {
        super(order, order);
        }

    /** Simple constructor.
     * Build a matrix with specified elements.
     * @param order order of the matrix
     * @param data table of the matrix elements (stored row after row)
     */
    protected SquareMatrix(int order, double[] data) {
        super(order, order, data);
        }

    /** Copy constructor.
     * @param m matrix to copy
     */
    protected SquareMatrix(SquareMatrix m) {
        super(m);
        }

    /** Get the determinant of the matrix.
     * @param epsilon threshold on matrix elements below which the
     * matrix is considered singular (this is used by the derived
     * classes that use a factorization to compute the determinant)
     * @return the determinant of the matrix
     */
    public abstract double getDeterminant(double epsilon);

    /** Invert the instance.
     * @param epsilon threshold on matrix elements below which the
     * matrix is considered singular
     * @return the inverse matrix of the instance
     * @exception SingularMatrixException if the matrix is singular
     */
    public SquareMatrix getInverse(double epsilon)
        throws SingularMatrixException {
        return (SquareMatrix) solve(new DiagonalMatrix (columns), epsilon);
        }


    /** Solve the <tt>A.X = B</tt> equation.
     * @param b second term of the equation
     * @param epsilon threshold on matrix elements below which the
     * matrix is considered singular
     * @return a matrix X such that <tt>A.X = B</tt>, where A is the instance
     * @exception SingularMatrixException if the matrix is singular
     */
    public abstract Matrix solve(Matrix b, double epsilon)
        throws SingularMatrixException;

    /** Solve the <tt>A.X = B</tt> equation.
     * @param b second term of the equation
     * @param epsilon threshold on matrix elements below which the
     * matrix is considered singular
     * @return a matrix X such that <tt>A.X = B</tt>, where A is the instance
     * @exception SingularMatrixException if the matrix is singular
     */
    public SquareMatrix solve(SquareMatrix b, double epsilon)
        throws SingularMatrixException {
        return (SquareMatrix) solve((Matrix) b, epsilon);
        }

    }



/**
   COPYRIGHT AND LICENSE

   Copyright (c) 2001-2005, Luc Maisonobe
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