> My MATLAB code isn't available at the moment. It shouldn't be a > problem translating it to Python. The problem is translating the Maple > code that derives the element matrices to Sage. I'm not exactly thrilled > with the design of the MATLAB code, but it works for my problems. I'd > probably make it object-oriented when converting it to Python.
And which exact symbolic features are still missing in Sage, if any? I mean, was the problem just that python is different than Matlab, or just because something in Sage should be improved? > What I mean by the derivation is the steps to get the finite element > approximation. There are two basic approaches to this. > > 1. Galerkin method - Convert the PDE to the weak form. > > 2. Ritz method - Requires a variational statement for the underlying > physical problem (e.g., Hamilton's Principle). The PDE is never > explicitly > formed since the FE approximation is used directly in the variational > statement. > > The Ritz method is less general, since you need an underlying > variational > principle, but it is easier to handle coupled equations. Getting the > weak form of the equations is difficult if the equations are coupled. > None of the introductory FE textbooks that I've seen covers it. Examples > always seem to use only one variable or multiple decoupled variables. > > For my problems, the Ritz method is applicable so I use it. > Unfortunately, > most packages assume you use Galerkin. In addition, they assume you > already > have the weak equations and like I've stated, getting them can be > challenging. > So, given that this is part of a symbolic package, there should be some > support for that. I got it now. Yes, I only need the Galerkin method. I have the equation, I have the weak form. Now I want to solve it, on a general geometry with general boundary conditions. I use libmesh for that: http://libmesh.sourceforge.net/ it's a very good FEM library. But still maybe it could be done simpler, using the SyFi approach or similar. Ondrej --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
