[aspect-devel] Development update: deal.II 8.5.0 and ASPECT 2.0.0.pre

[Rene Gassmoeller]

Hi all,

it has been a busy week in ASPECT's development and with the hackathon
approaching it is likely to stay that way at least for the next weeks.
Therefore I have switched the newsletter frequency to weekly until the
development cools down again (probably end of May). Nevertheless, there
have been two developments this week I would like to discuss and explain
a bit, since they are likely to affect all of us in some way.

1. With merging pull request #1456 (thanks Timo!) the development
version of ASPECT now requires deal.II 8.5.0 or newer, and the reference
test results are also created with that version. This will allow us to
clean some ugly code and use new features of deal.II during the
hackathon, and will also speed up some computations in spherical
geometries and all parallel models using particles. If you have used an
older version of deal.II before, your next upgrade of ASPECT will likely
take a bit more effort than usual, more so because of point 2.

2. As discussed at the last hackathon, ASPECT has developed a few
unfortunate naming conventions and other intricacies that are impossible
to fix in a compatible way. As we usually strive to keep plugins and
parameter files compatible to newer ASPECT version for as long as
possible, we have lived with some of those decisions for several years
now. However, the number of things we would have done differently if we
had the chance to change them grew over time. Therefore in a discussion
with all participants at the last hackathon we decided to make a major
version jump after ASPECT 1.5.0, consciously and sensibly breaking
existing files and plugins, and aim for a release of ASPECT 2.0.0 later
this year that again is stable for the years to come.

Within this week the first few of these breaking changes have been
implemented and will require updates to parameter files and source
plugins (boo!). However, in order to make the upgrade process as easy as
possible we introduced two conversion scripts in the doc/ directory that
will update most (if not all) files without manual work. Their usage is
explained in their comment sections, but to explain the 'most' in the
previous sentence: The script are simple 'find-and-replace' scripts, and
we can not guess your naming conventions for variables. If I e.g. had a
plugin with a private variable called 'tracer' that one might end up as
'particle' after the conversion, so please keep a backup of your files
and check the changes the scripts make for correctness. On the plus side
all of the code and parameter files within the official ASPECT
repository were converted with these scripts successfully, so we are
reasonably sure they work well.

As ASPECT 2.0.0 is far from out yet (current plans would be within the
last quarter of this year), there might be more significant changes
coming in, although we try to keep their number as small as possible and
merge them in batches to avoid frequent incompatible changes. Still, if
you have important deadlines looming, or simply do not need the newest
features, you might want to consider updating ASPECT only if necessary
in the next months, and be aware that it might involve a bit of work,
until ASPECT 2.0.0 is released.

The progress in major goals toward 2.0.0 is tracked in the github issue
#1090, and of course every major change will be listed on the website
http://aspect.dealii.org/doc/doxygen/changes_current.html. Please report
cases in which the update leads to problems on the mailing list so we
can see how to ease the transition.

Thanks for reading this wall of text,

Have a nice weekend,

Rene


-- 
Rene Gassmoeller
http://www.math.colostate.edu/~gassmoel/