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Dear All, Just an additional comment: If the BMRB knows how that error ought to be calculated, could the BMRB tell us? Otherwise they will be getting all kinds of funny numbers. Rasmus --------------------------------------------------------------------------- Dr. Rasmus H. Fogh Email: [log in to unmask] Dept. of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK. FAX (01223)766002 On Wed, 2 Mar 2011, Wayne Boucher wrote: > Hello, > > The standard deviation in Analysis is calculated using the actual peak shift > values, and so 0.0 usually means there is only one peak (or no peaks) for the > associated resonance. (If by complete luck all the resonance peaks happen to > have exactly the same shift value then you could still get 0.0 even with more > than one peak.) (The shift averaging can also be weighted by spectrum, so > you can say that some spectra are more, or less, accurate than others, for > example.) > > I guess the question now is how best to put in the information that the BMRB > wants, so where in the code. As Aleks says, the desired value is probably > the max of the standard deviation and the digital resolution (or maybe it > should be the sqrt of the sum of the squares, I don't know). Should this be > in the BMRB export code or somewhere "higher" up inside Analysis somewhere? > > Wayne > > On Wed, 2 Mar 2011, Aleksandras Gutmanas wrote: > >> Hi Catherine, >> >> Usually there is some precision with which you determine the chemical shift >> values based on digital resolution of your spectrum and linewidth of you >> peaks - basically a function of your spectrometer(s). In addition, CCPN >> Analysis would provide a non-zero error if your assignment is connected to >> more than one peak (right, Tim, Wayne?). The larger of the two values for >> each nucleus is what BMRB would need. >> In my experience, typical final values are in the range of 0.03-0.05ppm for >> 1H and 0.3-0.5ppm for 13C and 15N. >> >> Best, >> Aleks >>> Date: Tue, 1 Mar 2011 13:09:54 -0800 >>> From: Catherine Foo<[log in to unmask]> >>> Subject: chemical shift error / BMRB deposition >>> >>> I tried searching in the archives but could not find the answer >>> successfully (because "error" is not a very useful search term! :). >>> >>> I have submitted chemical shifts to BMRB and some of my error values >>> are 0.000, and BMRB wants me to provide the correct error information. >>> I'm not sure what sort of error BMRB is looking for, and I'm hoping >>> someone here with more experience could help me out. >>> >>> Am I correct in my assumption that analysis calculates error simply as >>> the standard deviation of all the corresponding peaks? >>> Is that the type of error that BMRB wants? >>> If I only have one peak picked for that resonance in my project, then >>> the SD is by definition zero? >>> >>> I am using analysis 2.0.7 and I exported the chemical shift list via >>> Format Converter. >>> >>> Cat >>> >> >