On Fri, 2012-12-07 at 13:57 -0800, Pavel Afonine wrote:
I had always assumed that experimental sigmas were somehow lumped into the alpha and beta parameters (esp. given your discussion in section 2.3). In principle they could be, right?
Yes, they could be.
I would like clarification on this. I was under impression (some of it formed by reading the papers) that it is not that experimental errors are "lumped" into beta, it is simply assumed that they are much smaller than "model error" and are therefore simply ignored because they are negligible. Alpha/beta are calculated in individual resolution shells. How can you "lump" experimental variance that varies by two orders of magnitude for individual reflections into a single parameter? I also wonder if introducing experimental uncertainty into Lunin's ML target is even possible without fundamentally altering it. It would remove ability to obtain analytical expressions for alpha/beta (also known as D/sigma_wc**2) as far as I can see. Which is the hallmark of this version of maximum likelihood target. Cheers, Ed. -- Bullseye! Excellent shot, Maurice. Julian, King of Lemurs.