[Ifeffit] Athena 0.8.014

[Bruce Ravel]

Hi folks,

I am pleased to announce a new version of Athena today.  The source
code tarball and windows executable are on my web site.  Today's
version offers three significant new features:

1.  A fairly major user-interface change
2.  The ability to fetch data files from web sites
3.  An improved merging algorithm

Please note that I am making use of a very recent feature of Ifeffit
(the "nofx" array function) in the new merging algorithm.  Windows
users need to update to the version of the big Ifeffit installer from
January 22, 2003.  Linux, Unix and OSX users should be using Ifeffit
version 1.0076 or later.  The Windows installer and the
ifeffit source code can be found at Matt's web site
  http://cars9.uchicago.edu/ifeffit/download.html

If you are not running Ifeffit 1.0076 or later, then merging WILL NOT
WORK in Athena 0.8.014.  So, please, upgrade.

I'll describe each of those features in detail below.

I'd like to specifically thank Matt (who suggested the web thing) and
Adam Web (who pointed out a problem with the merging algorithm).  I'd
also like to mention to all the people who have been asking for PCA in
Athena that it's moving closer to the front of my TODO list.  The
change to the user interface is needed to be able to put PCA into
Athena in a sensible manner.

Regards
B


The details about each new feature:

1.  Although the user interface change is pretty significant, I think
    it will be easy for current users to adapt to.  Indeed, I think
    most people will appreciate the added functionality that the
    change allows.  In earlier versions of Athena, data processing and
    analysis chores such as alignment, calibration, and log-ratio were
    done by interacting with a special dialog that popped up in a
    separate window. This separate window performed a grab, which
    means that you could not interact with the main window until you
    were done with the dialog and had dismissed it.

    Now, each of the various chores that previously used a pop-up
    dialog works by replacing the main part of the main window with
    the dialog specific to that analysis chore.  Thus, when you, say,
    go to align data, the part of the main window where you specify
    background removal and Fourier transform parameters gets replaced
    by various menus and entry boxes relevant to that chore.  If
    that's not clear, check out the new screenshots at
      
http://leonardo.phys.washington.edu/~ravel/software/exafs/screenshots.html#athena
    There are screenshots showing each of the eight alternate views in
    Athena.

    Not only does this reduce the number of windows that Athena throws
    up on the screen, it also allows you to use the groups list and
    the plotting buttons while one of the alternate views is
    displayed.  For example, you can now view one or more data groups
    in R-space *while* aligning.  Chores like alignment and difference
    spectra which require specifying a second data data group now work
    by selecting the second data group from the group list.

2.  You can now read data files from web sites using an extremely
    primitive interface.  In the File menu, there is an item which
    says "Open URL".  When you select this, the Echo area at the
    bottom of the screen gets replaced by a bright orange text entry
    box.  If you type in the fully resolved URL of a data file
    somewhere on the web, Athena will fetch and import that file.

    This is not extremely convenient because you have to type in the
    exact URL (or use cut and paste, of course).  I have not (yet)
    implemented a mouse-driven browser of any sort.  I may in the
    future if this feature proves popular.  One helpful feature I did
    implement is that Athena keeps a history of files downloaded
    during the current Athena session.  If you hit the up or down
    arrows while the URL text entry box has the focus, you will scroll
    up and down in the history of fetched data files.

    If you want to try it, I put some iron foil data on my web site.
    Enter this URL in the orange box:
       http://leonardo.phys.washington.edu/~ravel/misc/fe.060
    
    This feature will work for Windows users.  It will work for other
    platforms only if you have the LWP perl modules installed.
    Because that is a very large and frequently changing package, I am
    not comfortable distributing it with the horae package.  If you
    are a linux, unix, or OSX user and the "Open URL" thing is greyed
    out, then you will need to install LWP.  You can grab the latest
    version of the Bundle::LWP package from
      http://search.cpan.org/author/GAAS/libwww-perl-5.69/
    Alternately, you can use perl's CPAN interface.  At the command
    line, type
      perl -MCPAN -e shell
    then at the CPAN prompt type
      install Bundle::LWP

3.  The merging algorithm has changed.  Before, the marked data groups
    were merged after interpolating them onto the abscissa grid of the
    first marked group in the groups list.  Now, Athena determines
    what is the longest abscissa range common to all marked groups.
    The reason for this change is that the prior algorithm would
    extrapolate if a marked group had a shorter abscissa range than
    the first group.  Often this isn't a problem, but it can lead to
    very strange and undesirable results in the merged data.

    I am modestly confident that I have merging working correctly
    again in all cases.  I encourage anyone using the merging
    algorithm to send me a project file if they suspect that bugs
    remain. 
      

    
	
-- 
 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/