[Ifeffit] Different R-factor values

[Jason Gaudet]

Perhaps next time I'll notice the attachment ...

I don't see that "r factor for k-weight=..." in my old projects; I'm not
sure if I just never used that version?  I checked some Artemis 0.8.006
logfiles from 2009 and per-k-weight R-factors aren't in there, so that's a
little weird.

I'm still pretty sure, as you say, the overall R-factor is the
statistically meaningful one.

-Jason

On Fri, Jan 25, 2013 at 11:01 AM, Jason Gaudet <jason.r.gaudet at gmail.com>wrote:

> Hi Chris,
>
> Might be helpful also to link to the archived thread you're talking about.
>
> http://millenia.cars.aps.anl.gov/pipermail/ifeffit/2006-June/007048.html
>
> Bruce might have to correct me on this, but if I remember right there were
> individual-data-set R-factor and chi-square calculations at some point,
> which come not from IFEFFIT but from Bruce's own post-fit calculations, and
> these eventually were found to be pretty buggy and were dropped.
>
> I don't understand what "the average over the k weights" R factor is;
> analyzing the same data set with multiple k weights (which is pretty
> typical) still means a single fit result and a single statistical output in
> IFEFFIT, as far back as I can remember, anyhow.  The discussion about
> multiple R-factors is for when you're simultaneously fitting multiple data
> sets (i.e. trying to fit a couple different data sets to some shared or
> partially shared set of guess variables).
>
> I think the overall residuals and chi-square are the more statistically
> meaningful values, as they are actually calculated by the same algorithm
> used to determine the guess variables - they're the quantities IFEFFIT is
> attempting to reduce.  I don't believe I've reported the per-data-set
> residuals in my final results, as I only treated it as an internal check
> for myself.  (It would be nice to have again, though...)
>
> -Jason
>
> On Thu, Jan 24, 2013 at 10:12 AM, Christopher Patridge <
> patridge at buffalo.edu> wrote:
>
>>  I am reviewing some older analysis projects from artemis and just wanted
>> to know which R-factor more accurately describes the misfit?  I suspect the
>> average over the k weights values since this was adopted in Demeter?
>>
>> Thanks,
>>
>> Chris Patridge
>>
>> --
>> ********************************
>> Christopher J. Patridge, PhD
>> NRC Post Doctoral Research Associate
>> Naval Research Laboratory
>> Washington, DC 20375
>> Cell: 315-529-0501
>>
>>
>> _______________________________________________
>> Ifeffit mailing list
>> Ifeffit at millenia.cars.aps.anl.gov
>> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20130125/2c93b3fb/attachment.html>