Same here. Ultimately, the KD test must be used in the end to finalize the resolution (keeping in mind recently discussed issues of effective resolution given data completeness). I just want to add that at least some versions of aimless report overestimated resolution based on CC1/2 cutoff when outliers are present (e.g. due to ice rings or salt diffraction). It seems that aimless just picks the highest resolution bin where cc1/2> 0.5 even if some lower resolution bins are below 0.5 as well. I have written a script for more robust automated evaluation of these curves. In a nutshell, it fits CC1/2 (d) curve to 1/(1+exp (-x)) and returns the resolution at midpoint. I'm pretty sure that theoretical CC1/2 (d) dependence is different from this, but it seems good enough for a rough estimate.
Sent on a Sprint Samsung Galaxy S® III <div>-------- Original message --------</div><div>From: Roger Rowlett <rrowl...@colgate.edu> </div><div>Date:08/14/2014 5:44 PM (GMT-05:00) </div><div>To: CCP4BB@JISCMAIL.AC.UK </div><div>Subject: Re: [ccp4bb] CC-half value ?? </div><div> </div>Exactly. Aimless will give you suggested resolution cutoffs based on CC 1/2 in the log file. Roger Rowlett On Aug 14, 2014 5:04 PM, "conan仙人指路" <conan_...@hotmail.com> wrote: Hi Faisal, CC-half standard is valuable in evaluating the cut-off of highest resolution. Sometimes even if I/sigI is close to 1 and completeness is not as high, if CC-half is still significant, it may be worth incorporate the extra high-res shell data and extend the resolution. Again, if only the reliability and unbias are carefully confirmed, and the apparent significant CC-half is not due to an artifact of some other factors like ice ring etc. (Ref: Karplus PA and Diederichs K. 2012 Science 336, 1030-1033 https://www.pubmed.com/pubmed/22628654) It has yet to be appreciated by most population of the crystallography society, unlike the I/sigI, completeness, Rsym. In particular, Rsym has gradually less a direct measurement of the data quality and or determinant of resolution cut-off. Best, Conan Hongnan Cao, Ph.D. Department of Biochemistry Rice University Date: Fri, 15 Aug 2014 01:39:48 +0530 From: faisaltari...@gmail.com Subject: [ccp4bb] CC-half value ?? To: CCP4BB@JISCMAIL.AC.UK Dear all How CC-half value of a data set determines the maximum resolution limit during data processing ?? Although much we know about the Rsym and I/Isig values of the highest resolution shell while processing the data, what are the parameters we need to check related to CC-half values ?? -- Regards Faisal School of Life Sciences JNU
