NumPy performance: uint8 vs. float and multiplication vs. division?

Question

I have just noticed that the execution time of a script of mine nearly halves by only changing a multiplication to a division.

To investigate this, I have written a smal

Answer 1

It's because you multiply an int by a float and store the result as an int. Try your arr_mult and arr_div tests with different integer or float values for the multiplication / division. Especially, compare multiplying by '2' and multiplying by '2.'