Input u with corresponding output Au
Evaluate this code to see the image of vectors on the unit
circle (blue) under the mapping f(u) = Au.
You may make whatever edits to the code you like, but will most likely
want to limit your changes to ones on the matrix itself, replacing it
with another (real) 2-by-2 matrix.
The stepsize for t (set to 0.15)
results in the generation of approximately 42 frames for the animation.
It seems this is relatively close to predefined limits, for when the
stepsize is set to 0.1 (which would generate 63 frames), error messages
have been the result.