[stephencanon]

I hate to be that guy, but "Raphson", not "Rhapson" (http://en.wikipedia.org/wiki/Joseph_Raphson). It's also worth noting that no one ever actually forms the inverse of H, even if H is dense. At worst you would compute some factorization of H and use that to solve for the update d.

[aria]

Typo is fixed, thanks!

I think that's explicitly mentioned in the Quasi-Newton section that you only need to implicitly multiply and not form the matrix.

[tjl]

I still see it misspelt throughout.

[aria]

Want to try a refresh, I think it ought to be fixed now. Thanks