squarematrix.java

来自「一个一元曲线多项式数值演示例子」· Java 代码 · 共 94 行

package numbercruncher.matrix;

/**
 * A square matrix.
 */
public class SquareMatrix
    extends Matrix {
  //--------------//
  // Constructors //
  //--------------//

  /**
   * Constructor.
   * @param n the number of rows == the number of columns
   */
  public SquareMatrix(int n) {
    super(n, n);
  }

  /**
   * Constructor.
   * @param m the matrix (only the upper left square used)
   */
  private SquareMatrix(Matrix m) {
    set(m);
  }

  /**
   * Constructor.
   * @param values the array of values
   */
  public SquareMatrix(float values[][]) {
    set(values);
  }

  //---------//
  // Setters //
  //---------//

  /**
   * Set this square matrix from another matrix.  Note that this
   * matrix will reference the values of the argument matrix.  If
   * the values are not square, only the upper left square is used.
   * @param values the 2-d array of values
   */
  private void set(Matrix m) {
    this.nRows = this.nCols = Math.min(m.nRows, m.nCols);
    this.values = m.values;
  }

  /**
   * Set this square matrix from a 2-d array of values.  If the
   * values are not square, only the upper left square is used.
   * @param values the 2-d array of values
   */
  protected void set(float values[][]) {
    super.set(values);
    nRows = nCols = Math.min(nRows, nCols);
  }

  //-------------------//
  // Matrix operations //
  //-------------------//

  /**
   * Add another square matrix to this matrix.
   * @param sm the square matrix addend
   * @return the sum matrix
   * @throws numbercruncher.MatrixException for invalid size
   */
  public SquareMatrix add(SquareMatrix sm) throws MatrixException {
    return new SquareMatrix(super.add(sm));
  }

  /**
   * Subtract another square matrix from this matrix.
   * @param sm the square matrix subrrahend
   * @return the difference matrix
   * @throws numbercruncher.MatrixException for invalid size
   */
  public SquareMatrix subtract(SquareMatrix sm) throws MatrixException {
    return new SquareMatrix(super.subtract(sm));
  }

  /**
   * Multiply this square matrix by another square matrix.
   * @param sm the square matrix multiplier
   * @return the product matrix
   * @throws numbercruncher.MatrixException for invalid size
   */
  public SquareMatrix multiply(SquareMatrix sm) throws MatrixException {
    return new SquareMatrix(super.multiply(sm));
  }
}