Mailman 3 August 2010 - SfePy

next steps to Cython
by Robert Cimrman 16 Sep '10

16 Sep '10

As the release is out, we can now think about how to allow for Cython in our build process. The current build system is rather schizophrenic (numpy distutils and makefiles), so ideas which way to go are welcome. The process should be simple :o) r.

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update of geometries (reference element mappings)
by Robert Cimrman 27 Aug '10

27 Aug '10

Hi all, another step to better interactive use of SfePy was implemented today - the geometries (or reference mappings) are now created on the fly as needed. This simplified a lot of the code in sfepy.fem. If you only use the problem description files, you should not notice this change. Otherwise you might :-} Report back any problems, please. r.

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How to apply volume forces to subregion?
by oleg100 23 Aug '10

23 Aug '10

Hello! I try to apply constant volume forces to subregion (not whole domain). For example I use sfepy-release-2010.3/examples/standalone/interactive/ linear_elasticity.py I add follow line: ff=domain.create_region('ff','nodes in x < %.10f' % ( min_x + 0.1*(max_x - min_x))) And replace "omega" in line which define t2 with "ff". The result is error: ---------------------- sfepy: infs or nans in the residual: [-0.78190974 0. 0. ..., 0. 0. 0. ] sfepy: False > /srv/src/sfepy-release-2010.3/examples/standalone/interactive/sfepy/solvers/nls.py(197)__call__() 196 --> 197 if self.log is not None: 198 self.log(err, it) ipdb> -------------------------- What I do wrong?

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Shape optimization with SfePy
by Peter M Clausen 23 Aug '10

23 Aug '10

Hi I am looking for a framework for prototyping different stuff regarding shape optimization for development and research purposes related to our commercial optimization software TOSCA (www.fe-design.com). I was looking for a python framework with FE-capabilities and found SfePy which I find really exiting. Now, I've read most of the documentation, seen the fluid-shape optimization example (shapeOptim.py) which I have not debugged yet, but I am still missing some bricks to see the whole picture. I think my main problem is that I am missing the understanding the "objects" in SfePy. 1. Do you have a class-diagram or the like? Relations between problem, elements, nodes, material and terms is unclear for me. I believe you use many function pointers or something like that which throws me off. I have some experience programming Fortran, C++, Perl and some Python and maybe my Python skills are too bad... 2. Secondly, when I grasp what you are doing, I would like to implement a more general adjoint solver (the fluid problem is assuming self-adjoint or not?). In very general form I would like to: a) append linear adjoint loads (inheriting BCs from primary problem) with respect to my optimization problem, b) solve the primary and the adjoint loadcases c) save the solutions d) calculate sensitivities e) update nodal positions and goto b) Any helpful comments are very appreciated. Please excuse me if I use some mathematical expressions imprecise or incorrect - I am a mechanical engineer using mathematical methods to solve mechanical problems. The math is cool and interesting but second priority. :-) Best regards Peter M. Clausen

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note on installation help page
by osman 23 Aug '10

23 Aug '10

Hi Robert/team, I had to do a clean install of ubuntu-lucid due to careless changes I have made to the system python files. I could no longer use gtk.gtkgl which was needed. So, trying to get a working sfepy from clean ubuntu, I came across python-setuptools which is needed (used apt-get), and sympy 6.7 which needs to be built and installed locally just like scikits. I now have a correctly running sfepy again :-) Might help someone with less resolve to get sfepy working :-) Regards, -osman

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ANN: SfePy 2010.3
by Robert Cimrman 06 Aug '10

06 Aug '10

I am pleased to announce release 2010.3 of SfePy. Description ----------- SfePy (simple finite elements in Python) is a software for solving systems of coupled partial differential equations by the finite element method. The code is based on NumPy and SciPy packages. It is distributed under the new BSD license. Development, mailing lists, issue tracking: http://sfepy.org Documentation: http://docs.sfepy.org/doc Git repository: http://github.com/sfepy Project page: http://sfepy.kme.zcu.cz Highlights of this release -------------------------- - significantly rewritten code for better interactive use - cleaner and simpler high level interface - new tutorial section: - Interactive Example: Linear Elasticity [1] [1] http://docs.sfepy.org/doc/tutorial.html#interactive-example-linear-elastici… Major improvements ------------------ Apart from many bug-fixes, let us mention: - new examples: - demonstration of the high level interface - new tests: - tests of the new high level interface - simplified but more powerful homogenization engine For more information on this release, see http://sfepy.googlecode.com/svn/web/releases/2010.3_RELEASE_NOTES.txt (full release notes, rather long and technical). Best regards, Robert Cimrman and Contributors (*) (*) Contributors to this release (alphabetical order): Vladimír Lukeš, Osman, Andre Smit, Logan Sorenson

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report from EuroSciPy 2010
by Robert Cimrman 06 Aug '10

06 Aug '10

Hi, I am back. The conference was very nice, and several things are clear to me now: - sphinx was a good move (thanks, Logan!) - cython is the way to go for speed - writing a GUI with traits and mayavi should not be that difficult for a dedicated person (one guy did a very cool GUI for some brain imaging in six months as his master thesis at EPFL, without prior knowledge of Python...) Check out the conference site [0], all the slides should appear there sooner or later. Also, a very interesting collection of tutorials was assembled, see [1], (or [2] with my scipy.sparse tutorial, to be merged to [1]). r. [0] http://www.euroscipy.org/conference/euroscipy2010 [1] http://github.com/emmanuelle/Euroscipy-intro-tutorials [2] http://github.com/rc/Euroscipy-intro-tutorials

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preparing 2010.3
by Robert Cimrman 06 Aug '10

06 Aug '10

Hi, we are going to make a release soon (maybe tomorrow), so any testing of the current git master branch [1] would be welcome. I hope that not everyone is on holidays :) r. [1] http://github.com/sfepy/sfepy

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higher order elements
by Ondrej Certik 06 Aug '10

06 Aug '10

Hi guys, does sfepy allow higher order elements in 3D? So that one could use sfepy for a uniform p-FEM? One would need orders like 47, or even higher. Ondrej

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new docs: how to evaluate expressions
by Robert Cimrman 04 Aug '10

04 Aug '10

FYI: I have finally created some documentation on how to evaluate an expression involving sfepy terms given as string, see [1]. The new ProblemDefinition.create_evaluable() function has some nice properties that allow fast re-evaluation of the expression with different values of variables. r. [1] http://docs.sfepy.org/doc-devel/src/sfepy/fem/problemDef.html

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