[ccp4bb] counting constraints?

Protein crystallography Programs for crystallography X-ray detectors
Basic tutorials:
Protein Peptide

CCP4bb navigation

CCP4bb <-- 2008 <-- February 2008 <-- 14 February 2008

Previous message:
Subject: Re: Strange SFALL error
From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2008-02-14

Next message:
Subject: Re: counting constraints?
From: Bart Hazes bart {- dot -} hazes {- at -} UALBERTA {- dot -} CA
Date: 2008-02-14

Subject: counting constraints?
From: "Meyer, Peter" pameyer {- at -} MCW {- dot -} EDU
Date: 2008-02-14

Hi,

The recent discussion on Rwork/Rfree ratio reminded me of something I was wondering about (*). When counting constraints as observations for determining the observation to parameter ratio, is each unique constraint counted, or each time a given constraint is used. For example, if there are 4 carbon oxygen bonds (assuming the same parameters, let's say serine beta-carbon to serine gamma-oxygen), would this count as 4 constraints as observations, or 1?

Intuitively, it seems to me like it should be counting unique constraints (although as near as I can tell these aren't listed in refmac5 logfiles). But I don't have a clear explanation for why, and of course I could be wrong on this.

Thanks,

Pete

* Rough translation - I'm about to ask another stupid question. Not like it's the first time.

CCP4bb navigation

CCP4bb <-- 2008 <-- February 2008 <-- 14 February 2008

Previous message:
Subject: Re: Strange SFALL error
From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2008-02-14

Next message:
Subject: Re: counting constraints?
From: Bart Hazes bart {- dot -} hazes {- at -} UALBERTA {- dot -} CA
Date: 2008-02-14