[Ifeffit] k range

[Scott Calvin]

I have an addition to Shelly's "practical" advice:

2e) Try the fit at different k-weights. (If you were fitting at multiple
k-weight simultaneously, try one k-weight at a time.) In my experience,
with a reasonable k-range you may find the statistical quality of your fit
(r-factor, chi-square) changes markedly, but the fitted parameters should
not drift outside of the ranges defined by their uncertainties. If they do,
it is either a sign that you should reduce the k-range or that you have a
tenuous and unstable fit that should be viewed with considerable skepticism.

--Scott Calvin
Sarah Lawrence College

At 04:03 PM 4/27/2004 -0500, you wrote:
>2) Pull your data into Artemis.  Use the good k-range that you
>determined from step one.  
>2b) Determine a model that works and look at the results including the
>uncertainties.
>2c) Increase the k-range and compare the results.  Try to decrease kmin
>and increase kmax.  Do one thing at a time and see how the results vary.
>You will need to make a lot of comparisons, see how your results and
>uncertainties change as you adjust these values.  
>2d)  Decide on a k-range that gives you the "best" results.
>>Shelly
>