Re: [ccp4bb]: bins in sfall

["Eleanor J. Dodson" <ccp4@ysbl.york.ac.uk>]

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Have you read the documentation?

In particular look at RSCB which describes how the resolution range for 
scaling is set.
The NBIN asimply controls the output - not the way the scale is calculated..
  That uses this sort of equation:

                   Sum {(SCALE * Fcalc) * (Fobs)}
  i               --------------------------------------
                    Sum {(SCALE * Fcalc) * (SCALE * Fcalc)}


where the scale to be minimised is is kexp(-bs**2)

All the low resolution terms are excluded from a Wilson scaling 
procedure , since the Wilson statistics do not hold there. This means 
that the R factor in the low resolution bins will be higher.
There is no solvent correction applied either so the agreemment wil not 
be as good as from REFMAC or CNS

  Eleanor

Richard Baxter wrote:
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> 
> Dear All,
> 
> I am running SFALL to calculate structure factors from a model. I
> understand that FP,SIGFP can be scaled to FC in the process. My questions 
> is, how is this scaling done, as compared to the other CCP4 programs that 
> scale data (SCALEIT, RSTATS?). Is it multiplying by <FC>/<FP> for some
> number of bins? Is this the same number of bins for calculating R-factor
> vs. resolution (i.e. set by BINS keyword, default is 50)?
> 
> thanks for your help,
> 
> Richard Baxter
> 
> 
> 
>