Re: ANN: SfePy 2012.4

On Wed, Nov 21, 2012 at 1:25 PM, Robert Cimrman wrote:

On 11/21/2012 08:52 PM, Ondřej Čertík wrote:

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On Wed, Nov 21, 2012 at 10:08 AM, Robert Cimrman wrote:

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I am pleased to announce release 2012.4 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.

Home page: http://sfepy.org Downloads, mailing list, wiki: http://code.google.com/p/sfepy/ Git (source) repository, issue tracker: http://github.com/sfepy

Highlights of this release -------------------------- - initial support for hierarchical basis on quadrilateral and brick elements

Are there some examples of this? I would be curious to see how it works.

Yes, see [1]. The computation is as fast as with the Lagrange basis. What takes time is the linearization of the solution for visualization, as that is written in pure Python.

r. [1] http://sfepy.org/doc-devel/examples/diffusion/sinbc.html

Thanks. I was able to compile it and run it after applying the following patch: diff --git a/examples/diffusion/sinbc.py b/examples/diffusion/sinbc.py index 9d30aed..7448191 100644 --- a/examples/diffusion/sinbc.py +++ b/examples/diffusion/sinbc.py @@ -31,7 +31,7 @@ from sfepy.fem import Mesh, Domain from sfepy.fem.meshio import UserMeshIO, MeshIO from sfepy.homogenization.utils import define_box_regions -base_mesh = data_dir + '/meshes/elements/2_4_2.mesh' +base_mesh = data_dir + '/sfepy/meshes/elements/2_4_2.mesh' def mesh_hook(mesh, mode): """ I just installed sfepy using the usual "python setup.py install", but I wasn't able to run it inside the tree, it was telling me: Traceback (most recent call last): File "./simple.py", line 19, in <module> from sfepy.applications import PDESolverApp File "/home/ondrej/repos/sfepy/sfepy/applications/__init__.py", line 2, in <module> from pde_solver_app import (PDESolverApp, solve_pde, solve_evolutionary, File "/home/ondrej/repos/sfepy/sfepy/applications/pde_solver_app.py", line 7, in <module> from sfepy.fem import ProblemDefinition File "/home/ondrej/repos/sfepy/sfepy/fem/__init__.py", line 6, in <module> raise ImportError( msg ) ImportError: sfepy extension modules are not compiled! type "make" So I just copied ./simple.py and sinbc.py out of the tree (into /tmp) and applied the patch above and things started to work. I have a few more basic questions so that I fully understand sfepy's terminology: What kind of basis functions does it use? I looked it up here: http://sfepy.org/doc-devel/src/sfepy/fem/poly_spaces.html "Lagrange elements" are just the usual Lagrange interpolation polynomials with nodes at Gauss-Lobatto points? What exactly are the "Lobatto" shape functions? Are those the "integrated Legendre polynomials"? Is this basis also called "hierarchical"? I noticed that the refined mesh uses (first order) hanging nodes? I assume the hanging nodes only work with the "Lobatto" shape functions? (That's why you commented that the computation is as fast as with the Lagrange basis.) Ondrej