'interactive' solutions

Hi!
Please forgive me, if the question is either trivial or far beyond aster's capabilities. I am a newbie to the aster software and need to know if cases can be solved 'interactively', before I can take a decision whether aster suits my needs.

By 'interactively' I mean the following:
Let's take an elastic deformation model as an example. The user should be able to define and change loads and displacements at any surface and any time. Given a sufficiently small model, the solution should then be available in (or close to) real time.
Afaik the usual procedure in aster is, that it reads the mesh, boundary conditions etc., then assembles the FEM system matrices and solves or integrates the system. If any parameter changes, the whole process is reiterated, although the matrices may not have changed - only the right hand side has.

My question is, whether it is possible to hook subroutines into the aster code. These subroutines may extract the system matrices, modify parameters and state of the system, and later initiate a new, efficient solution reusing as much as possible of the previously extracted data structures.

Probably this has been done before. Can you point me to some tutorial-style description of the necessary steps? Or which sections of the aster documentations are relevant (I have a hard time reading French, so I can't get a quick overview of all the docs. But if I know what I need, I'll be able to translate it). I'm not only interested in elasticity models, so if you can answer my question for any other case, I'm happy, too.

Finally, if this should be impossible with aster, could you answer the same question for openfoam or elmer?

Thank you,
Kathi<br /><br />Post edited by: Kathi, at: 2008/02/09 01:30

Hi Kathi

Code-Aster is more flexible as most of the commercial codes which I know. But the cost of this is more learning and knowlege in order to use all these possiblities.

After a first run, where You store the Code-Aster-database, You can make (a) subsequent run(s) using all data structures which have been stored. This way You can reuse Yur assembled matrices.

Generating, storing and (later) reading system matrices is done with normal EFICAS-commands, no subroutines are nessecary for this.

Furthermore, You can use Python-code in Your command file in order to manipulate data structures.

I must admit that I am not an expert on these special things, You should better ask (also in english) in the Code-Aster-forum at www.code-aster.org.

overview in english on Code-Asters capabilities is here:
www.code-aster.org/V2/IMG/pdf/plaq_V7_GB.pdf

Regards, Johannes

Thank you for the useful hints. I did my best quickly reading the documents in the user manuals section, but I am afraid that this software is too complicated for my limited experience.

Before I give up, one more question. You write &quot;Furthermore, You can use Python-code in Your command file in order to manipulate data structures.&quot; From what I read, it is not clear to me, whether the command files are true python code, or whether they follow some kind of python-like language.
Can you give an actual example or cite the section of one of the manuals, where I can find how to call my own python code which is not part of Aster? It is fine, if my python code must be included in the command file. But can I use all 'import' statements, 'def function():', etc.?

Kathi

&gt;&gt;Can you give an actual example or cite the section of one of the
&gt;&gt;manuals, where I can find how to call my own python code which is not
&gt;&gt;part of Aster?

Go to
/www.code-aster.org/
then Dokumentation, then Examples, then Utilisation de Python

&gt;&gt;But can I use all 'import' statements, 'def function():', etc.?
As far as I know, yes.

Good luck, Johannes