John, I think the problem is different from what you presume.
You have measured a *very* short data range. The archive post you cite is not really relevant. This one is: http://www.mail-archive.com/ifeffit@millenia.cars.aps.anl.gov/msg03717.html There are two issues that need addressing given the data you provided. Issue #1: As I explain in that mailing list posting, you are doing yourself no favors measuring data in a range from -40 to +70 or so. Such data are almost impossible to normalize consistently and defensibly. Issue #2: Your data point out some shortcomings in Athena. Athena should deal more gracefully when given ridiculous input like your much-too-short data files. Here is a short list of things that Athena is doing wrongly: 1. The default values for the pre-edge line are both allowed to be outside the data range. This is actually the primary cause of your problems. Because both pre-edge parameters are before the beginning of the data, the determination of the pre-edge line fails. Trying to plot the pre-edge line or normalized data, then also fails. This problem is exacerbated by the fact that you are measuing Mo. For such a heavy element, the default value for the upper bound of the pre-edge region is -45. Your data begin at about -38. 2. As long as the data are flagged as being XANES data (something Athena does to avoid wasting time attempting to find a background function for very short data range), it is not possible to recover from problem 1. I had to change the data type [1] to mu(E) in order to correctly compute the pre-edge line. 3. Athena provides no feedback that the source of the problem is extremely short data range and poor choice of pre- and/or post-edge line parameters. Athena should do some sanity checking and complain about the potential problem. I will attempt to address the problems Athena has with data like this for the next release. You should reconsider your measurement strategy the next time you go to the synchrotron. B [1] http://bruceravel.github.com/demeter/aug/ui/glist.html#informationaboutitemsinthegrouplist On Tuesday, February 19, 2013 03:33:26 PM John Hayes wrote: > Hello, > > I am having some issues when importing multiple data sets into Athena. When > I try to import more than one file at a time only the reference sample data > from the first file are imported and the subsequent files do not import the > reference data (only a straight line is imported). There is an error that > is reported, and I have saved the error log [log.txt] and attached it in > the zip file (as well as the dathena.log file and some sample spectra > files). The spectra files are of the Mo K-edge and the reference is an Mo > foil. These spectra were collected using the HXMA beamline, and as such, I > am using the HXMA plug-in to import the data. The relevant columns for the > reference are: > > col 2: energy > col 6: I1 > col 7: I2 > > I searched the archive and found what I think is a similar issue (link: > www.mail-archive.com/ifeffit@millenia.cars.aps.anl.gov/msg03454.html), and > hope I'm not over-reporting the error (sorry in advance if I am), but the > previous report seemed somewhat different, in that there was an issue with > the wrong edge being chosen for the test and ref data (best I can tell). I > do have the work around of importing each file individually, so this is no > more than an inconvenience, but I thought I'd report it and see if maybe > someone had some up with a more elegant solution. > > I am currently using version 9.14 on a 64-bit windows platform. > > Thanks in advance for any advice or help the community can provide! -- Bruce Ravel ------------------------------------ bra...@bnl.gov National Institute of Standards and Technology Synchrotron Methods Group at NSLS --- Beamlines U7A, X24A, X23A2 Building 535A Upton NY, 11973 Homepage: http://xafs.org/BruceRavel Software: https://github.com/bruceravel _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit