On Wednesday 04 February 2004 01:40 pm, dmc@pdx.edu wrote:

Ifeffit Dudes,

I've tried to plot several groups together in Athena and then saved them together under "Save Marked Groups---chi(k)." It seems to work fine, but then when I try to open it up in Artemis I can't do anything. If I try to graph something, it closes. I can't do a fit b/c there are no parameters. My question is this: how can I average and then fit several data files?

Dan, Dude! You have hit upon a serious problem in the interaction between the two programs. You want to save several chi(k) spectra to a single file and then use Artemis to fit one or more of those spectra. That is a reasonable thing to want to do. Sadly, it is not possible in the current version of Artemis. Here is what you should do instead: Save each chi(k) spectra that you may want to analyze to an individual file using the File menu entry that says "Save chi(k)". This will save a two column data file that Artemis will have no trouble importing. You will then have one file for each of these spectra. In Artemis, you can use the feature for *changing* the current data file when you want to switch between them. I originally included the "Save marked groups" thing in Athena for the sake of exporting many spectra from Athena into a plotting program like Kaleidagraph or XMGrace. In that case it is convenient to have a single file with many spectra rather than many files. For some completely inexplicable reason, it never occured to me that someone would want to use the marked-groups output file in the manner that you want. Interestingly, you are not the first person in the last week to point this out to me. So, in the short term, you will have to use Athena to write out individual data files. I will address this issue in the next version of Artemis. Thanks for posting that message! B P.S. It may not be entriely clear, but you can certainly merge data, then save the merged spectrum to an individual file without saving any of the data that went into the merge. That is, you can write data groups to output files even when there is not an input file associated with the data group (as would be the case for a merged spectrum). -- Bruce Ravel ----------------------------------- ravel@phys.washington.edu Code 6134, Building 3, Room 222 Naval Research Laboratory phone: (1) 202 767 5947 Washington DC 20375, USA fax: (1) 202 767 1697 NRL Synchrotron Radiation Consortium (NRL-SRC) Beamlines X11a, X11b, X23b National Synchrotron Light Source Brookhaven National Laboratory, Upton, NY 11973 My homepage: http://feff.phys.washington.edu/~ravel EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/