Bruce, thanks for the info.. When referring to the Edge Step feature you mentioned that: "You can type in a number, as before" This does not appear to be working, if I check "Fix Step", enter a value into the edge step window, and then recompute the background, the value of the edge step reverts back to the automatic value. Dave
-----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of Bruce Ravel Sent: Thursday, June 02, 2005 3:00 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Importance and Edge Step
On Thursday 02 June 2005 13:06, Barton, David (DG) wrote:
I noticed two new features in Athena 0.8.040 and am unsure of how to use them. The new features are "Importance" and "Edge Step". I attempted to use the Edge Step feature by checking "Fix Step" and then entering a value, but the Edge Step always reverts back to the automated value. However, when I use the Increase/Decrease buttons (Left/Right arrow in Edge Step window) the edge step does change, but it only changes in increments of 0.01 which is much too large for my datasets. Is there something I am missing here?
Also, I couldn't locate Bruce's changelog for Athena so I am unsure of what the new "Importance" feature does. Anyone used this new feature yet?
Importance: This number is used only in a merge and only when the "Weight by importance" button in the Merge menu is checked. It's intention is to allow user-specified weights in a merge. If you trust one data set twice as much as another, the more trusted one might be given an importance of 2 while the other is given an importance of 1. This was in response to a feature request -- personally I am not clear how would know how to weight different data sets.
Edge step: I got a request for a quick way to play around with the size of the edge step. When the "fix step" button is checked, you can then specify an edge step which will then be used to normalize the data. You can type in a number, as before, or you can tweak the edge step up or down. You can set the size of the tweak in the preferences using bkg->step_increment. Note that if the "fix step" button is not checked, the edge step will be recomputed every time the background is recalculated.
And I do need to be more conscientious about updating the change logs. Sorry.
B
-- Bruce Ravel ----------------------------------- bravel@anl.gov -or-
ravel@phys.washington.edu Environmental Research Division, Building 203, Room E-165 Argonne National Laboratory phone and voice mail: (1) 630 252 5033 Argonne IL 60439, USA fax: (1) 630 252 9793
My homepage: http://feff.phys.washington.edu/~ravel EXAFS software: http://feff.phys.washington.edu/> ~ravel/software/exafs/
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