[Ifeffit] energy resolution
bravel at bnl.gov
Mon Apr 20 11:24:10 CDT 2015
On 04/20/2015 12:01 PM, Lisa Bovenkamp wrote:
> Now here is question 1:
> What is the combination of the two profiles in the Athena peak fitting routine for the Pseudo-Voigt?
Athena uses Ifeffit for this. Ifeffit's pseudo-Voight function is
(Larch's is explained here:
In Athena, gamma is the mixing parameter for the pseudo-Voight.
That said, this might not be doing quite what you are looking for.
Ifeffit's implementation uses the same width for both functions (as does
Larch), which does not seem to be what you are asking for.
I suppose you could try using two lineshapes, one Gaussian and one
Lorentzian, which share a value for the centroid. That is possible in
Athena as long as you don't float the centroids. While floating a
common centroid is possible in both Ifeffit and Larch, there is no way
to indicate that in Athena. I'm not sure off the top of my head how to
interpret the amplitudes in that situation to extract a value equivalent
Perhaps Athena isn't the right tool for the job? Or perhaps you can
figure out something that does what you want using either Ifeffit or
(preferably!) Larch? In that case, let me know and I'll see about
including it in Athena.
Bruce Ravel ------------------------------------ bravel at bnl.gov
National Institute of Standards and Technology
Synchrotron Science Group at NSLS-II
Upton NY, 11973
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