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Hi all,

Anthony Duff wrote (regarding R-fac and R-free from mapfiles?)
> 2.  CNS does a worse job of refining a structure in the late stages,
even
> accounting for differences in default restraint weights.  (I don't know
why
> this would be so, with both using maximum likelihood... maybe the CNS
algorithms are inferior?)

This reminded me of a question I've been wondering about for a bit: Does
maximum likelihood refer to a scoring function (generate gradients to
optimize while refining), or both a scoring function and refinement
menthod?  As far as I understand, it's the first (based on what I've seen
of poking around in the internals of programs that do ML refinement vs
other types of refinement).  But least-squares is a special case of
maximum likelihood, and least-squares (again as far as I know) is both a
scoring function and refinement method.

Could somebody more knowledgable about maximum likelihood clear this up?

Thanks,

Pete


Pete Meyer
Fu Lab
BMCB grad student
Cornell University








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