So figuratively, I'm trying to win a nuclear war with a stick. :rofl: I did not take any course in PDEs, I just self-studied some of them, and now I'm toast. :rofl: First, please feel free to hurl rocks at me if my simplification is incorrect: https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-prn2/t1/q71/1545789_719161698116788_1463986171_n.jpg Second, how do you discretize ∂2u/(∂x∂y)? Is it: (ux+1,y - 2ux,y + ux-1,y)(ux,y+1 - 2ux,y + ux,y-1)/((xi+1 - xi)(yi+1 - yi)) I might have a few more questions after this. Sorry if everything I'm saying is incorrect, please don't be harsh. I'm telling the truth when I say that we didn't cover this in our numerical methods class and I didn't take a PDE course. Thanks!