Dear community, The minimum working code example is based on the ft03_heat.py tutorial, which describes a time dependent poisson equation and is governed by the following equations: u’=Δu+f in the unit square u=uD on the boundary (Dirichlet boundary conditions) u=u0 at t=0 I tried to implement …

Your are missing a super init in the expression class, see: [image] RecursionError: maximum recursion depth exceeded in the ft11_magnetostatics.py example of the "Solving PDEs in Python - The FEniCS tutorial Part 1" mesh The tutorial is out of date. Change your Permeabilit…

Dear Cou assemble(u*dx) is integrating over the whole domain, not only between x\in [0,0.1]. I believe you want to declare a function, without any class, but for a part of the domain. Since the domain is 2-D, space_dim=2 so your domains is a list of lines not surfaces. Consider using domains = Mes…

Thanks a lot @dokken and @bilenemek ! I implemented the super init, but was not able to get the MWCE from the first post running. Hence, I simplified the example and was able to realize a time dependent UserExpression, but I´m struggeling to implement an additional dependence of space. That’s my cu…

The issue is that you have now mixed the methods eval and eval_cell, as well as adding the t argument to the eval_cell input, which is stored by the class. The following works: from dolfin import * mesh = UnitSquareMesh(10,10) class MySourceConcentration(UserExpression): def __init__(self, t,…

Thanks @dokken for your ongoing support. Without your help, this wouldn´t be possible. I was able to get the MWCE of the first post running, although I had to use v = TestFunction(V) instead of your suggestion to use v = project(f,V), because this resulted in an error message. Do you see any proble…

Beginner struggels with object-oriented programming to compute a time-, space- and u-dependent source term

variational formulation

dokken April 16, 2020, 2:34pm 2

Your are missing a super init in the expression class, see:

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Beginner struggels with object-oriented programming to compute a time-, space- and u-dependent source term

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