[Ifeffit] notes for figures
ravel at phys.washington.edu
Fri Nov 22 15:45:29 CST 2002
MN> I respectfully disagree. This is a common question for ifeffit,
MN> and how to do this and other manipulations and embellishments to
MN> the plot window are well documented.
Mea culpa! I should have said no one has ever asked _me_ for that
MN> A GUI is a fine thing -- and more than one is even better -- but
MN> they are not the whole story. Maybe it should be made more clear
MN> to new users that artemis (or was it athena -- I couldn't tell??)
MN> is built on top of ifeffit, and that the command line is
MN> available and sometimes even useful?
Indeed! Another way to say this is that Athena and Artemis are only
good and useful because Ifeffit is so very good and very useful.
As good as GUIs might be, they are always limited to doing only the
things for which there are buttons or menu items. If you need to do
something beyond the scope of the GUI, usually you are sunk.
Fortunately, that is not quite the case with my GUIs. For one thing
you can always go to the command box that I indicated in my last email
message and type in any ifeffit command. That is very handy for any
twiddling that you may want to do within the context of using Athena
and Artemis. Indeed, all the graphical trickery performed by Athena
and Artemis serves to generate lengthy sequences of ifeffit commands.
All the hard work (background removal, FTs, fitting, plotting) is done
by ifeffit. Athena and Artemis are no more than clever bookkeepers.
Even better, you can access ifeffit directly in a variety of ways.
* You can run the "ifeffit" program (for you windows users, that is
what the icon that says "Ifeffit Shell" does) and interact
directly by typing in commands.
* You can write ifeffit scripts using a text editor. These are
extended sequences of ifeffit commands which can be read into the
ifeffit program using the "load" command.
* You can use the perl, python, or tcl wrappers thoughtfully
provided by Matt with the ifeffit distribution to write you own
high level programs which combine the best features of those
excellent languages with the exafs and numerical functionality of
If you read my recent paper on an anomalous diffraction experiment
(Appl. Phys. Lett. 81:15 p. 2812), you will see that all of the
analysis was done using ifeffit and none using Athena or Artemis. I
wrote a variety of scripts which made extensive use of ifeffit's
splendid "minimize" command. The Lorentzian fit in Figure 2 and the
fit to the energy dependent diffraction data in Figure 3a both
involved ifeffit's minimize command.
Matt provides extensive documentation on how to use ifeffit directly.
Check out this web page:
The Reference Manual in particular is my constant companion when I am
coding up new stuff for my codes.
Bruce Ravel ----------------------------------- ravel at 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, X24c, U4b
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/
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