[Ifeffit] Re: Ifeffit digest, Vol 1 #38 - 6 msgs

[Raul Barrea]

Hi Matt,
             first of all I'd like to say that I have been using Iffefit and
Athena for a while and I found both packages very easy to learn and use.
I've been following the discussion about how Ifeffit and also athena manage
continuous scans and finer grid in energy space. We work in continuous scan
mode at BioCAT, so our energy grid cannot be change during the scan as step
scans usually do and our energy grid is aprox 1 eV per point, so when we
transform this grid to k space we get a not even grid and for most of our
point the grid is really smaller than 0.05 A-1. I was very curious about the
statistics and how ifeffit and Athena calculate the interpolation. I took
one of our scans taken at the  Cu K Edge and I remove every other point from
it. In order to preserve the grid in the very first region of K I just
substitued the high K region from 6 to 13 A-1 with this "new" grid. I found
that the results of the original data and the modified data are exactly the
same, so the interpolation is not considering the missing points. I've also
removed a group of three consecutive points of a goupr of five from the grid
(in the same k region) and I found the same results. It will be very usefull
if you could include into your package other method that consider every
measured point. As you said in your last mail working with finer grid could
be a non trivial change but if you could include a better interpolation
method will be great. Attached you will fine the three files with the
original data and the modified ones (senc-full.xmu; senc-1.xmu and
senc-3.xmu).

Thanks

Raul

Raul A. Barrea, PhD
Senior Research Associate
Illinois Institute of Technology
7900 S Cass Av.
BioCAT/APS, Bldg 435B
Argonne, IL 60439
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