>200x disparity in computation time between computers

[johncoxon]

A student and I are working together on some data and using aacgmv2 to convert some coordinates.

On their machine (AMD Ryzen 5 3600):

%timeit convert_mlt(np.arange(90), dt.datetime(2015, 1, 1))
2.19 ms ± 69.2 us per loop (mean ± std. dev. of 7 runs, 100 loops each)

On my machine (Apple M1 Ultra):

%timeit convert_mlt(np.arange(90), dt.datetime(2015, 1, 1))
509 ms ± 24.8 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

So, on my computer, the process is more than 200x slower than on theirs.