[rosstex]

I don't even know what course you'd learn matrix calculus in, but it was a necessity for my upper level ML courses. This website would have been a godsend, and would have spared TAs many hours figuring out what knowledge we were missing. We got by with the Wikipedia page...

[joshvm]

High level computer science courses straddle several disciplines and you end up with weird stuff like computer vision being the purview of the electrical engineering department. EEs tend to know some of this stuff because a lot of matrix algebra comes up in control/optimisation theory.

In physics we did matrix calculus primarily for electromagnetism and fluid dynamics. Maxwell's equations are the first time most students see the div/curl operator and it's also used in e.g. Navier-Stokes. But even though we were taught it, I don't think we really bothered to remember what a "Jacobian" is.

A lot of this stuff also comes up in physical rendering.