public Matrix(int new_width, int new_height) throws MatrixError {
        width = new_width;
        height = new_height;
        verifySize();
        
        array2d = new int[height][width];
        lengths2d = new int[height][width];
        
        for (int i=0; i<width; i++) {
            for (int j=0; j<height; j++) {
                array2d[j][i] = 1;
                lengths2d[j][i] = 1;
            }
        }
    }