matrix.java

MacroWeka扩展了著名数据挖掘工具weka

/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program 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 General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


/*
 *    Matrix.java
 *    Copyright (C) 1999 Yong Wang, Eibe Frank, Len Trigg, Gabi Schmidberger
 *
 */

package weka.core;

import java.io.Writer;
import java.io.Reader;
import java.io.LineNumberReader;
import java.io.Serializable;
import java.util.StringTokenizer;

/**
 * Class for performing operations on a matrix of floating-point values.
 * <p/>
 * Deprecated: Uses internally the code of the sub-package 
 * <code>weka.core.matrix</code> - only for backwards compatibility.
 *
 * @author Gabi Schmidberger ([e-mail])
 * @author Yong Wang ([e-mail])
 * @author Eibe Frank ([e-mail])
 * @author Len Trigg ([e-mail])
 * @author Fracpete (fracpete at waikato dot ac dot nz)
 * @version $Revision: 1.1 $
 * @deprecated Use instead <code>weka.core.matrix.Matrix</code> - only for
 * backwards compatibility. 
 */
public class Matrix 
  implements Cloneable, Serializable {

  /**
   * The actual matrix */
  protected weka.core.matrix.Matrix m_Matrix = null;

  /**
   * Constructs a matrix and initializes it with default values.
   *
   * @param nr the number of rows
   * @param nc the number of columns
   */
  public Matrix(int nr, int nc) {
    m_Matrix = new weka.core.matrix.Matrix(nr, nc);
  }

  /**
   * Constructs a matrix using a given array.
   *
   * @param array the values of the matrix
   */
  public Matrix(double[][] array) throws Exception {
    m_Matrix = new weka.core.matrix.Matrix(array);
  }

  /**
   * Reads a matrix from a reader. The first line in the file should
   * contain the number of rows and columns. Subsequent lines
   * contain elements of the matrix.
   *
   * @param r the reader containing the matrix
   * @throws Exception if an error occurs
   */
  public Matrix(Reader r) throws Exception {
    m_Matrix = new weka.core.matrix.Matrix(r);
  }

  /**
   * Creates and returns a clone of this object.
   *
   * @return a clone of this instance.
   * @throws Exception if an error occurs
   */
  public Object clone() {
    try {
      return new Matrix(m_Matrix.getArrayCopy());
    }
    catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }

  /**
   * Writes out a matrix.
   *
   * @param w the output Writer
   * @throws Exception if an error occurs
   */
  public void write(Writer w) throws Exception {
    m_Matrix.write(w);
  }

  /**
   * returns the internal matrix
   * @see #m_Matrix
   */
  protected weka.core.matrix.Matrix getMatrix() {
    return m_Matrix;
  }

  /**
   * Returns the value of a cell in the matrix.
   *
   * @param rowIndex the row's index
   * @param columnIndex the column's index
   * @return the value of the cell of the matrix
   */
  public final double getElement(int rowIndex, int columnIndex) {
    return m_Matrix.get(rowIndex, columnIndex);
  }

  /**
   * Add a value to an element.
   *
   * @param rowIndex the row's index.
   * @param columnIndex the column's index.
   * @param value the value to add.
   */
  public final void addElement(int rowIndex, int columnIndex, double value) {
    m_Matrix.set(
        rowIndex, columnIndex, m_Matrix.get(rowIndex, columnIndex) + value);
  }

  /**
   * Returns the number of rows in the matrix.
   *
   * @return the number of rows
   */
  public final int numRows() {
    return m_Matrix.getRowDimension();
  }

  /**
   * Returns the number of columns in the matrix.
   *
   * @return the number of columns
   */
  public final int numColumns() {
    return m_Matrix.getColumnDimension();
  }

  /**
   * Sets an element of the matrix to the given value.
   *
   * @param rowIndex the row's index
   * @param columnIndex the column's index
   * @param value the value
   */
  public final void setElement(int rowIndex, int columnIndex, double value) {
    m_Matrix.set(rowIndex, columnIndex, value);
  }

  /**
   * Sets a row of the matrix to the given row. Performs a deep copy.
   *
   * @param index the row's index
   * @param newRow an array of doubles
   */
  public final void setRow(int index, double[] newRow) {
    for (int i = 0; i < newRow.length; i++)
      m_Matrix.set(index, i, newRow[i]);
  }
  
  /**
   * Gets a row of the matrix and returns it as double array.
   *
   * @param index the row's index
   * @return an array of doubles
   */
  public double[] getRow(int index) {
    double[] newRow = new double[this.numColumns()];
    for (int i = 0; i < newRow.length; i++)
      newRow[i] = getElement(index, i);

    return newRow;
  }

  /**
   * Gets a column of the matrix and returns it as a double array.
   *
   * @param index the column's index
   * @return an array of doubles
   */
  public double[] getColumn(int index) {
    double[] newColumn = new double[this.numRows()];
    for (int i = 0; i < newColumn.length; i++)
      newColumn[i] = getElement(i, index);

    return newColumn;
  }

  /**
   * Sets a column of the matrix to the given column. Performs a deep copy.
   *
   * @param index the column's index
   * @param newColumn an array of doubles
   */
  public final void setColumn(int index, double[] newColumn) {
    for (int i = 0; i < numRows(); i++)
      m_Matrix.set(i, index, newColumn[i]);
  }

  /** 
   * Converts a matrix to a string
   *
   * @return the converted string
   */
  public String toString() {
    return m_Matrix.toString();
  } 
    
  /**
   * Returns the sum of this matrix with another.
   *
   * @return a matrix containing the sum.
   */
  public final Matrix add(Matrix other) {
    try {
      return new Matrix(m_Matrix.plus(other.getMatrix()).getArrayCopy());
    }
    catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }
  
  /**
   * Returns the transpose of a matrix.
   *
   * @return the transposition of this instance.
   */
  public final Matrix transpose() {
    try {
      return new Matrix(m_Matrix.transpose().getArrayCopy());
    }
    catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }
  
  /**
   * Returns true if the matrix is symmetric.
   *
   * @return boolean true if matrix is symmetric.
   */
  public boolean isSymmetric() {
    return m_Matrix.isSymmetric();
  }

  /**
   * Returns the multiplication of two matrices
   *