[Ifeffit] smoothing XAS data

[Felix E. Feiten]

Dear Daria,

as you stated the fitting result is very similar for the smoothed and 
unsmoothed data.
So I think the answer to some commenters' question "Why do you smooth 
the data?" is that it just looks better.

First of all, if you smooth your data you must, obviously, say so and 
explain how you did the smoothing when publishing/presenting these 
results.

Secondly, the quality of the raw EXAFS data is an important measure of 
how good the measurement is. Smoothing it will remove this information. 
This is a strong argument to NOT use smoothing.

When you do Fourier-Transformation from k-space to R-space (and possibly 
back from R-space to q-space) this automatically smooths the data. I am 
aware that this is a filtering of frequencies rather than "real" 
smoothing, but it will give the effect you want: The data will look less 
noisy.

In conclusion, I would suggest never smoothing, instead showing the 
back-transform from R-space to q-space if you want to have nice looking 
curves but your data are not that good but ALWAYS supplying raw data in 
publications.

With kind regards,

Felix

-- 
Dr. Felix E. Feiten
Fritz-Haber-Institut der Max-Planck-Gesellschaft
Department of Interface Science
Faradayweg 4-6
14195 Berlin

phone: +49 30 8413 4142