# A heads up on Chebfun

The applied side of approximation theory is like black magic to me: even if I don’t want to do research in the area, at least I respect it enough to find it interesting. So, I recommend bit-player’s post on Nick Trefethen’s Chebfun package. Especially check out the links (Trefethen’s an engaging author).

# Verify these matrix properties (easy and fun)

I’m looking at products like $$\mat{G}^t \mat{A} \mat{G}$$ where the columns of $$\mat{G}$$ are (nonisotropic) normal vectors. Specifically, I’d like to know the distribution of the eigen/singular-values of this product. Surprisingly, I was unable to find any results in the literature on this, so I started reading Gupta and Nagar to see if I could [...]