SfePy March 2009

sfepy@python.org

3 participants
6 discussions

mayavi2 + gentoo
by Robert Cimrman 17 Mar '09

17 Mar '09

Good news everyone! Atleast everyone using gentoo. If you want to use mayavi for 3D visualtization, install the ebuild dev-python/ets-3.1.0 (with proper ACCEPT_KEYWORDS (I have used ~amd64), perfectly safe!). The installation was smooth and it works like a charm! r.

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better progress bar
by Ondrej Certik 17 Mar '09

17 Mar '09

Hi, I just discovered this very nice progressbar: http://nadiana.com/animated-terminal-progress-bar-in-python and it looks so nice, that I think we should have this in sfepy. :) It's BSD, so no problem. Ondrej

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slip/no-slip BC
by Robert Cimrman 11 Mar '09

11 Mar '09

Hi, I have just created the issue [1] aiming at implementing the slip/no-slip boundary conditions. Is there anybody here with some experience in this field? Several ways come to my mind: 1. adapt the existing linear combination BC (LCBC) (see [2]) to nonzero right-hand side - the LCBC allow imposing \sum_{i=1..N} a_i u_i = 0 for the dofs u_i and coefficients a_i. We need \sum_{i=1,2,3} n_i u_i = g. 2. enforce the condition via the Lagrange multipliers, leading to a saddle point system, 3. ? Any comments would be appreciated! r. [1] http://code.google.com/p/sfepy/issues/detail?id=82 [2] http://sfepy.kme.zcu.cz/cgi-bin/moin.cgi/SfePy/Examples#RigidBodyMotion

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added broyden solvers
by Robert Cimrman 09 Mar '09

09 Mar '09

Hi all, I have recently added some matrix-free (quasi-Newton) nonlinear solvers - just simple wrappers around some methods of scipy.optimize. It was originally meant for the schroedinger application, but the nice thing is that they work for other problems too, e.g. the Poisson equation, try the attached patch - no matrix is assembled during the computation. r. diff --git a/input/poisson.py b/input/poisson.py index b98e381..50b6ee9 100644 --- a/input/poisson.py +++ b/input/poisson.py @@ -134,6 +134,17 @@ solver_0 = { #! --------------------------- #! Even linear problems are solved by a nonlinear solver (KISS rule) - only one #! iteration is needed and the final rezidual is obtained for free. +solver_10 = { + 'name' : 'broyden', + 'kind' : 'nls.scipy_broyden_like', + + 'method' : 'broyden3', + 'i_max' : 50, + 'alpha' : 0.5, + 'M' : 5, + 'w0' : 0.00, + 'verbose' : True, +} solver_1 = { 'name' : 'newton', 'kind' : 'nls.newton', @@ -159,7 +170,7 @@ solver_1 = { #! Use them for anything you like... Here we show how to tell which solvers #! should be used - reference solvers by their names. options = { - 'nls' : 'newton', + 'nls' : 'broyden', 'ls' : 'ls', }

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ANN: SfePy 2009.1
by Robert Cimrman 02 Mar '09

02 Mar '09

I am pleased to announce the release of SfePy 2009.1. SfePy (simple finite elements in Python) is a finite element analysis software based primarily on Numpy and SciPy. Mailing lists, issue tracking, git repository: http://sfepy.org Home page: http://sfepy.kme.zcu.cz Major improvements: - new solvers: - simple backtracking steepest descent optimization solver - PETSc Krylov solvers via petsc4py, sequential mode - LOBPCG eigenvalue solver (SciPy implementation) - new mesh readers: - mesh3d (hermes3d) - AVS UCD ascii mesh - Hypermesh ascii mesh - homogenization framework: - unified approach to resolve data dependencies: HomogenizationEngine class - switched DVCS from mercurial to git Applications: - phononic materials: - dispersion analysis, phase velocity computation for phononic materials - caching of coefficients to speed up parametric runs - schroedinger.py: - fixed DFT iterations, iteration plot saving - basic smearing around Fermi limit For more information on this release, see http://sfepy.googlecode.com/svn/web/releases/2009.1_RELEASE_NOTES.txt Best regards, Robert Cimrman

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preparing release 2009.1
by Robert Cimrman 02 Mar '09

02 Mar '09

Hi all, It is almost three months from the last release (2008.4), so I would like to roll out the 2009.1 by the beginning of the next week. I am aware that this list has been rather silent recently, but if some lurkers are still here, I would very appreciate testing/reporting bugs for the development version, see below. If you have some comments on how to improve our web site(s) [1], [2], do not hesitate and post it here, please. I am aware that the documentation is lacking, we are working on that, as well as on fixing the issues. [1] http://sfepy.org [2] http://sfepy.kme.zcu.cz To help with the testing, proceed as follows: 0. Make sure the prerequisities [3] are installed. 1. Get the sources: $ git clone git://git.sympy.org/sfepy.git or: go to [4] and download the tarball of the latest snapshot 2. Build extension modules: $ cd sfepy $ make # you may need to tweak site_cfg.py, see site_cfg_template.py 3. Run tests: $ ./runTests.py all the tests should pass: 26 test file(s) executed in 78.13 s, 0 failure(s) of 34 test(s in case some tests fail, rerun them as follows: $ ./runTests.py tests/test_<failing test file>.py --debug and post the output here, or (better) as a new issue at [5] 4. Try examples: $ python examples/compare_elastic_materials.py $ python examples/rs_correctors.py 5. Try some scripts: $ ./script/convert_mesh.py -h $ ./script/blockgen.py -h [3] http://code.google.com/p/sfepy/wiki/Installation [4] http://code.google.com/p/sfepy/wiki/Downloads?tm=2 [5] http://code.google.com/p/sfepy/issues/list Thank you! r.

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SfePy March 2009