E1: Initialize! The red point will be at (+1, 0), the point to be added to the array at (1, i)
Follow the construction of the subtraction in the u plane for all points of the array.
E2: Change the length of the subtracted vector without changing its direction. How and to what degree does that shift the array in the u plane?
E3: Rotate the subtraction vector What is the result the in the u plane? Try to formulate it quantitatively.
E4: Change both vectors. What determines the length (r) and the direction (angle) of the difference vector? Why does the orientation and the size of the array not change?
E5: Repeat the experiment for a single point by reducing the array to a point.