Based on the simulations I've done the data should be "cut" at CC1/2 = 0. Seriously. Problem is figuring out where it hits zero.
Alternately, if French & Wilson can be modified so the Wilson plot is always straight, then the data don't need to be "cut" at all. As for the "resolution of the structure" I'd say call that where |Fo-Fc| (error in the map) becomes comparable to Sigma(Fo). This is I/Sigma = 2.5 if Rcryst is 20%. That is: |Fo-Fc| / Fo = 0.2, which implies |Io-Ic|/Io = 0.4 or Io/|Io-Ic| = Io/sigma(Io) = 2.5. Makes sense to me... -James Holton MAD Scientist On Aug 27, 2013, at 5:29 PM, Jim Pflugrath <jim.pflugr...@rigaku.com> wrote: > I have to ask flamingly: So what about CC1/2 and CC*? > > Did we not replace an arbitrary resolution cut-off based on a value of Rmerge > with an arbitrary resolution cut-off based on a value of Rmeas already? And > now we are going to replace that with an arbitrary resolution cut-off based > on a value of CC* or is it CC1/2? > > I am asked often: What value of CC1/2 should I cut my resolution at? What > should I tell my students? I've got a course coming up and I am sure they > will ask me again. > > Jim > > From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Arka > Chakraborty [arko.chakrabort...@gmail.com] > Sent: Tuesday, August 27, 2013 7:45 AM > To: CCP4BB@JISCMAIL.AC.UK > Subject: Re: [ccp4bb] Resolution, R factors and data quality > > Hi all, > does this not again bring up the still prevailing adherence to R factors and > not a shift to correlation coefficients ( CC1/2 and CC*) ? (as Dr. Phil > Evans has indicated).? > The way we look at data quality ( by "we" I mean the end users ) needs to be > altered, I guess. > > best, > > Arka Chakraborty > > On Tue, Aug 27, 2013 at 9:50 AM, Phil Evans <p...@mrc-lmb.cam.ac.uk> wrote: > The question you should ask yourself is "why would omitting data improve my > model?" > > Phil
