Mixed formulation for Poisson equation

Question

Hello, I have downloaded demo_mixed-poisson.py from https://fenicsproject.org/olddocs/dolfin/2016.1.0/python/demo/documented/mixed-poisson/python/documentation.html but when I was trying to run this script I have faced with one issue:

    Traceback (most recent call last):
  File "demo_mixed-poisson.py", line 52, in <module>
    W = FunctionSpace(mesh, BDM * DG)
TypeError: __init__() takes at least 4 arguments (3 given)

What was that, how can I handle it? Thank you.

Comments

Hi, what version are you using? (from terminal run dolfin-version)

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dolfin-version is 1.5.0

Answer 1

That's too old due to changes in the MixedFunctionSpace, see here under 2016.1.0 section. The demo code you can run with your version can be found here.

Comments

ok, thank you.

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This demo for version 1.5.0 can also be found at https://fenicsproject.org/olddocs/dolfin/1.5.0/python/demo/documented/mixed-poisson/python/documentation.html. The complete documentation for 1.5.0 is at https://fenicsproject.org/olddocs/dolfin/1.5.0/