/// <summary>
/// Constructs and returns a new matrix with <i>width</i> columns and <i>height</i> rows which is a copy of the contents of the given box.
/// The box ranges from <i>[column,row]</i> to <i>[column+width-1,row+height-1]</i>, all inclusive.
/// </summary>
/// <param name="column">the index of the column-coordinate.</param>
/// <param name="row">the index of the row-coordinate.</param>
/// <param name="width">the width of the box.</param>
/// <param name="height">the height of the box.</param>
/// <returns></returns>
/// <exception cref="IndexOutOfRangeException">if <i>column<0 || column+width>columns() || row<0 || row+height>rows()</i></exception>
public BitMatrix Part(int column, int row, int width, int height)
{
if (column < 0 || column + width > _columns || row < 0 || row + height > _rows)
{
throw new IndexOutOfRangeException("column:" + column + ", row:" + row + " ,width:" + width + ", height:" + height);
}
if (width <= 0 || height <= 0)
{
return(new BitMatrix(0, 0));
}
BitMatrix subMatrix = new BitMatrix(width, height);
subMatrix.ReplaceBoxWith(0, 0, width, height, this, column, row);
return(subMatrix);
}
