[Ifeffit] Athena (Demeter 0.9.26) does not import all datapoints from ascci file

[Prüßmann, Tim (IKFT)]

Hi Matt,

the rebin screen was just to show the number of data points.

We used column 1 as energy and column 9 as numerator; data type ‘xanes’; no preprocessing.
Overall we used identical parameters in 0.9.25 and 0.9.26

The “plan” is to do the standard calibration and normalization steps, but we lose data points by just importing the data. In the example Kathy sent, we go from 275 “real” points to 109 imported points.

This effect appears with all Spec files we have tested (measured at different times and to different beamlines -> different number of columns).

Importing data from FEFF and FDMNES works, we get the same number of points as in the ascii file.

I also tried the XAS Viewer in Larch (0.9.37), which read all points of the Spec file. I exported the data as Athena project and .csv
Importing the project file into Athena works and the “about current group” function shows 275 points. However, nothing can be plotted, the plot window stays on the overview from the import screen.
The csv file contains all 275 points, but importing to Athena again reduces it to 109 points.


Tim



From: Ifeffit [mailto:ifeffit-bounces at millenia.cars.aps.anl.gov] On Behalf Of Matt Newville
Sent: Tuesday, March 27, 2018 2:12 AM
To: XAFS Analysis using Ifeffit
Subject: Re: [Ifeffit] Athena (Demeter 0.9.26) does not import all datapoints from ascci file

Tim, Kathy,

I did not respond to Kathy's earlier email, and I apologize for letting it falling off my radar screen.

FWIW, I do not see the same problem. I can read the file (with the Spec plugin enabled) and plot the data.  There are 275 data points.   Reading multi-column files from can be tricky (should we know which columns you chose or what processing steps you took).   And spec files can cause no end of trouble.  But from the screenshots aattached, it looks like maybe Time meant to rebin the data.  Is that related to what Kathy was trying to do?

Perhaps you could explain what steps you took in reading the data file and more clearly explain the problem?  Like, did you intend to re-bin the data?

For sure, the plot labeled as coming from PyMCA looks strange to me --- the derivative of the data has clearly been smoothed from the raw data in the file.  I don't know what to make of that.

Hope that helps,

--Matt

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