![](https://secure.gravatar.com/avatar/764323a14e554c97ab74177e0bce51d4.jpg?s=120&d=mm&r=g)
1 Mar
2023
1 Mar
'23
8:21 a.m.
On Wed, Mar 1, 2023 at 10:30 AM Matthew Brett <matthew.brett@lis.ac.uk> wrote:
I think I'm right that we've had our own custom implementation of Powell for a very long time - it looks to me (from git blame) that Travis O put a version of the current code in with commit b94c30dcb (April 2002).
For what it's worth, it's not so much "our own custom implementation" so much as following a particular published variant that was explained (but not originally published in) *Numerical Recipes*. Interestingly, that chapter claims that the modification is to assist Powell's method in handling long skinny valleys. -- Robert Kern