<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
</head>
<body>
<p>This letter contains three announcements:</p>
<ul>
<li>Publication of the BornAgain reference paper in J. Appl.
Cryst.</li>
<li>Changes in development team</li>
<li>Release 1.17</li>
</ul>
<h2 id="reference-paper-">Reference paper</h2>
<p>A comprehensive description of BornAgain has been published as an
open-access
article in the Journal of Applied Crystallography:</p>
<blockquote>
<p>G. Pospelov, W. Van Herck, J. Burle, J. M. Carmona Loaiza, C.
Durniak, J. M. Fisher, M. Ganeva, D. Yurov and J. Wuttke,
BornAgain: software for simulating and fitting grazing-incidence
small-angle scattering. J. Appl. Cryst. 53, 262-276 (2020)</p>
</blockquote>
<blockquote>
<p><a
href="http://scripts.iucr.org/cgi-bin/paper?S1600576719016789,">http://scripts.iucr.org/cgi-bin/paper?S1600576719016789,</a>
<a href="https://doi.org/10.1107/S1600576719016789">https://doi.org/10.1107/S1600576719016789</a></p>
</blockquote>
<p>This is intended to be the canonical reference for many years to
come;
please cite this article whenever refering to the BornAgain
project.
Additionally, please continue to document the use of a specific
software
version by an appropriate citation as suggested <a
href="https://www.bornagainproject.org/documentation/howto/cite">here</a>.</p>
<h2 id="change-in-development-team-">Change in development team</h2>
<p>Walter Van Herck and Dmitry Yurov have left our group to reorient
themselves
geographically or/and career-wise. Walter has been one of the two
lead
developers since the start of the project in 2012. Dmitry joined
in 2017
with funding from the European Spallation Source. We are very
grateful to
Walter and Dmitry for their lasting contributions to BornAgain.</p>
<p>In the meantime two new research software engineers have joined
the team,
Alexander Schober and Randolf Beerwerth. Alexander has been with
the MLZ
Scientific Computing Group since 2018, and has so far worked on
two data
reduction projects. He is now supporting Gennady in a deep
overhaul of the
GUI, in view of its generalization to reflectometry. Randolf has
been with
us since February 2020; he is currently working on the
reflectometry core
and on polarization support.</p>
<h2 id="release-1170-">Release 1.17.0</h2>
<p>Today, <a moz-do-not-send="true"
href="https://www.bornagainproject.org/download/">BornAgain
1.17.0</a> has been released.</p>
<p>New Core functionality includes the Nevot-Croce roughness model,
support
for switching between roughness models and reflectometry engines,
and a few
new form factors (cantellated cubes, rectangular ripples). The API
has changed
for ripples, as described in a new section of the form factor
catalog.</p>
<p>Changes in the GUI mainly address visual issues on
high-resolution displays.
This may result in some compatibility issues with previous
versions.</p>
<p>Much of this release is devoted to internal consolidation and
speedup.</p>
<ul>
<li>Standard reflectometry computations become ill conditioned at
vanishing
transmissions. Previously, we addressed this issue with a
bifurcation.
We have now implemented a new linear algorithm that is much
faster for
samples with many layers.</li>
<li>The spheroid form factor is now computed without numeric
integration.
Thanks to Matt Thompson (Australian National University) for the
suggestion.</li>
<li>Continuous integration tests have been put under control of
GitHub Actions,
and tentatively been moved to GitHub’s own cloud service. This
will reduce
waiting times, and thereby make development faster and smoother.
Thanks to
Andrew Nelson (ANSTO) for insights from the GitHub Actions
script he wrote
as part of his reflectometry software cross-validation efforts.</li>
</ul>
<p>We have stopped distributing BornAgain for Python 2.7. We
recommend switching to
the latest Python, 3.8. The CMake minimum required version has
changed
to 3.14. The minimum supported MacOS version is now 10.13. For
building under
Linux, we recommend Ubuntu 20.04 LTS Focal / Debian 11 bullseye.</p>
<p>There are three new examples:</p>
<ul>
<li><a
href="https://www.bornagainproject.org/documentation/examples/reflectometry/roughness-model/">Specular
simulation with different roughness models</a></li>
<li><a
href="https://www.bornagainproject.org/documentation/examples/reflectometry/basic-polarized-reflectometry/">Basic
polarized reflectometry</a></li>
<li><a
href="https://www.bornagainproject.org/documentation/examples/fitting/extended/real-life-reflectometry/">Reflectometry:
Real life fitting</a></li>
</ul>
<p>More details are in the CHANGELOG, the <a
href="http://apps.jcns.fz-juelich.de/redmine/versions/51">issue
tracker</a>, and the git history.</p>
<p>As always, we very much welcome your comments and feedback!</p>
</body>
</html>