[Ifeffit] Fwd: Re: r-factor

[Bruce Ravel]

On Friday 23 June 2006 05:01, you wrote:
> I have a question about Artemis log file. I noticed that two r-factors are
> reported in the log file. One is in the fifth line and it is called
> 'R-factor'  and the other one is under the data set fitting conditions and
> it is called 'r-factor for this data set'. They have in general different
> values. What does it mean? Which is the difference between the two?

It probably means that I am calculating something wrongly.

Here's the concept.  If you do a multiple data set fit and you have
some value of R-factor, you would like to know how that misfit is
partitioned among the data sets.  That is, you'd like to know if one
set is contributing to the misfit for significantly than the others.

When Ifeffit computes the R-factor, it is for the entire fit.  My idea
in Artemis was to use the formula for R factor from page 18 of
   http://cars9.uchicago.edu/~newville/feffit/feffit.ps
on each data set in a multiple data set fit and report that in the log
file.

At some point, I must have convinced myself that I was doing the
calulcation in Artemis identically to how it is done in Ifeffit.  If
you are seeing different values, it would seem I was mistaken.

I'll make an entry in my to do list to look into that.

B

-- 
 Bruce Ravel  ---------------------------------------------- bravel at anl.gov

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