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Hi.</div>
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Just wanted to give another perspective based on how we might do this in dune-fem:</div>
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the way I would suggest doing this is to store the parameters defining your domain in a</div>
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discrete function over a `FiniteVolumeSpace`. This gives you then exactly one value per</div>
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entity (possibly a bit of an overkill since it is a double by default but that could be useful as</div>
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mention below). Then</div>
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(a) local grid refinement and coarsening is taken care automatically., i.e., the material
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properties are transferred to the new elements in the mesh when calling grid.adapt()
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(b) (when using Python bindings) you can directly use this discrete function as UFL coefficient when describing the UFL form using `ufl.conditional`. Unfortunately `ufl.conditional` isn't</div>
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very nice to use but since I didn't so far have an application I didn't look more into ufl</div>
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and subdomains. So in fact instead of defining the material property discrete function
<br>
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by setting an integer on each cell I would directly use the finite volume discrete function
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to store the material properties - at least if this is not prohibitive w.r.t. memory, i.e., it</div>
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depends on how many material properties have to be set. Assuming it is only a few values</div>
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(r) then one could setup a finite volume discrete function with range dimension r and</div>
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directly use that within the ufl expression for the model. Again adaptivity would be handle</div>
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automatically as mentioned in (a).</div>
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Just some thoughts</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Andreas<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Dune <dune-bounces@lists.dune-project.org> on behalf of Christian Engwer <christian.engwer@uni-muenster.de><br>
<b>Sent:</b> 06 April 2020 16:39<br>
<b>To:</b> HELFER Thomas 202608 <thomas.helfer@cea.fr><br>
<b>Cc:</b> dune@lists.dune-project.org <dune@lists.dune-project.org><br>
<b>Subject:</b> Re: [Dune] Handling several materials</font>
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<div class="BodyFragment"><font size="2"><span style="font-size:11pt;">
<div class="PlainText">> In case of adaptative remeshing, would those modules update individual domains, so I<br>
> would not have to care about those technicalities you mentionned ?<br>
<br>
If you use local adaptivity you will always have to make sure your<br>
data is present on the adapted mesh. Usually this requires some<br>
interpolations and so on. In a similar way we now also have to<br>
transfer these indices. And additionaly from the "Gmsh" mesh to your<br>
actual mesh object.<br>
<br>
If you would opt for multidomain or subgrid. Things wuld be<br>
significantly more complecated. You would safe some work, because you<br>
don't transfer the parameters between meshes (as you have exactly one<br>
parameter set per subdomain), but you will have to setup Problems mit<br>
many different subdomains and extract the list of cells in one<br>
subdomain from your gmsh file (so you will need again the initial<br>
indices).<br>
<br>
Ciao<br>
Christian<br>
<br>
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