Dear Matt

Thank you for your reply.

I confirmed that chi (k) becomes smooth by the Savitzky-Goley method by doing the attached lar file.

I will try on various conditions from now.

I may also ask if there is something I do not understand.

Thank you for your help again!

Bests,

Yuji Mahara

From: Ifeffit [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of Matt Newville
Sent: Thursday, April 20, 2017 5:26 AM
To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov>
Subject: Re: [Ifeffit] The difference of EXAFS oscillation when using Athena and when using Larch

Hi Yuji,

The attached larch script (a modification of your script but note: not python, so you may have to add a bunch of '_larch=mylarch' arguments) to show the effects of smoothing with Savitzky-Golay and of interpolating onto a "classic XAFS energy grid".   You might want to play around with this different options.  It definitely seems that none of these methods are systematically over-smoothing the data and reducing the amplitudes of the oscillations -- one more reason to use Larch instead of Ifeffit.  But it also seems like smoothing this data with a Savitzky-Golay fitler is helpful.

Also attached are plots showing k- and R-space generated from the attached script.

--Matt