def _create_and_rotate_coordinate_arrays(self, x, y, orientation):
<EOL>pattern_y = np.subtract.outer(np.cos(orientation)*y, np.sin(orientation)*x)<EOL>pattern_x = np.add.outer(np.sin(orientation)*y, np.cos(orientation)*x)<EOL>return pattern_x, pattern_y<EOL>
Create pattern matrices from x and y vectors, and rotate them
to the specified orientation.