More in the matrix algebra scheme of things.

A document with some more handy relations.

I hate BLAS/LAPACK interfacing so much. And there are, like, two pages that talk about it on the internet. I might have to change that.

EDIT: I wrote, like, 6 wrappers for BLAS/LAPACK functions today. It was painful. There are two websites that talk about this on the internet (and the lecture notes I have from my statistical computing course). That's it. Two. Everybody else, of course, has figured out how to use the C library interfaces and therefore don't think about it. It's also annoying because, you know, if I chained these things together instead of wrapping each individual function, it would be much more efficient. That's why they were made in the weird way they were. But doing it that way involves a lot of magic and debugging.