On 5/8/07, Alasdair McAndrew <amca01 at gmail.com> wrote:
>
> A very quick look over brent.c seems to indicate that it is either based
> on the NR code, or that both brent.c and the NR code share a common
> ancestor.
Well, I certainly hope they share a common Algol 60 ancestor: Brent did
after all publish the algorithm! (R.P. Brent, "An algorithm with guaranteed
convergence for finding a zero of a function" Computer Journal 14:4:422-425
(1971) doi:10.1093/comjnl/14.4.422). Whether brent.c is derived from NR or
not, I don't know. I also don't know whether the NR algorithm has enough
original content to pass the "creativity" threshold required by copyright
law (I doubt it) -- remember, copyright protects the expression of ideas,
not the ideas themselves.
Brent also offers a clear description of what the algorithm is and isn't
guaranteed to do in his article and book.
-s