[Ifeffit] Larch 0.9.17 available for download and testing

Matt Newville newville at cars.uchicago.edu
Tue Dec 18 15:18:52 CST 2012

Hi Folks,

I'm happy to announce the first full release of Larch, the next
generation of Ifeffit.  This includes a kit for source installation
and a binary installer for Windows.  A primitive Larch GUI is included
that provides a command-line interface and a browser / help system for
data in the Larch session.  Essentially all the EXAFS and XANES
functionality of Ifeffit 1,2 is reproduced in Larch, with several
significant improvements.  The current version (0.9.17) should still
be considered "beta" software in that bugs should be expected, but
Larch is now ready for detailed "field-testing" and use.  It you're
using Ifeffit for scripting (that is, not using the GUIs Athena,
Artemis, SixPack, or Prestopronto that call Ifeffit), you should start
using Larch now.

Several months ago, I described the goals and status of Larch (see
which is still accurate.  Since then, the biggest effort has been in
documentation, finishing some of the details of Feffit() fitting, and

Larch is available at

Any feedback on any part of Larch is welcome.  I am especially
interested in hearing reports from people trying the Windows installer
-- I've tested it only on 3 Windows7 machines.  I also reiterate my
plea for people to get involved in the development and extension of
these tools.  A main motivation for Larch's implementation and design
was to make it very easy to add new features and experiment with new
algorithms and methods for analysis.  If you're interested in helping
Bruce or I develop these codes, please let us know.

Some of you may have noticed that support for the Ifeffit 1.2 series
has been very poor recently, including the fact that building for Mac
OS X has fallen far behind.  With this release of Larch, I'm very
happy to formally end support for Ifeffit 1.2.  I'm willing to use,
and help others use, the older versions of Ifeffit, Athena, etc, but
there will be no more releases or bug fixes for the Ifeffit 1.2
series.  The code is available if someone else wants to maintain it.


--Matt Newville

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