class DiagonalMatrix extends AbstractRealMatrix implements Serializable {

    @Override
    public double getEntry(final int row, final int column)
        throws OutOfRangeException {
        MatrixUtils.checkMatrixIndex(this, row, column);
        return row == column ? data[row] : 0;
    }

    public  DiagonalMatrix(final int dimension);
    public  DiagonalMatrix(final double[] d);
    public  DiagonalMatrix(final double[] d, final boolean copyArray);

}