<html><head><style type="text/css">body {word-wrap: break-word; background-color:#ffffff;}</style></head><body><div style="font-family: sans-serif; font-size: 16px">Hi Volker, <br>actually i think you are correct with all your assumptions. About one week ago i noticed that the hanging node howto example does not work anymore. However i was not yet able to look into it. I'll try to tackle it next week. However, if you find the problem before me, feel free to send a patch. <br><br>Best Regards, Felix<br><br><font face="sans-serif"><span style="font-size: 14px"><i><font color="#333333">Durch MOTOBLUR™ verbunden</font></i></span></font></div><br><br>-----Ursprüngliche Nachricht-----<br><blockquote style="; border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><div style="font-family: sans-serif; font-size: 14px"><b>Von: </b>schauer <schauer@mechbau.uni-stuttgart.de><b><br>An: </b>dune-pdelab <dune-pdelab@dune-project.org><b><br>Gesendet: </b>Mi, 23 Mrz 2011, 16:30:04 MEZ<b><br>Betreff: </b>[dune-pdelab] Hanging Nodes<br><br></div>Dear PDELabers,<br><br>I try to implement hanging nodes together with Dirichlet constraints. I <br>acted as in the poisson example of the pdelab howto. <br><br>But now some things appear strange to me:<br><br>- The transformation of a vector with <br> gos.backtransform <br><br> as well as<br> <br> gos.forwardtransform<br> <br> only seem to multiply the hanging node entry of the input-vector <br> with a value from the constraints container without any kind of<br> interpolation with the neighbouring nodes - so the transformation<br> matrix is diagonal and in my case the backward transformation after a<br> forward transformation do not give the original vector but in my case <br> these transformations even seem to be identical. <br><br>I then looked at the constraints container with the verbosity flag in<br>the constraints call, and also saw that all the hanging nodes had just<br>one entry with the same line as row index, e.g. like:<br><br>266: (266,0.25) <br>267: (267,0.25) <br>268: (268,0.25) <br>275: (275,0.5) <br>276: (276,0.5) <br>278: (278,0.5) <br><br>which also consists of only one value in every row (somehow I supposed<br>the neighbouring, non-constrained nodes should show up here). <br><br>The row entries of the resulting matrix at a hanging node position were<br>trivial, which seems to be fine to me, but I don't think that the other<br>rows were changed correctly (though I didn't verify).<br><br>I suppose these things can also be verified on the hanging nodes example<br><a href="poisson.cc">poisson.cc</a> of the pdelab-howto.<br><br><br>So is the way the constraints container gets filled for the hanging<br>nodes wrong - or am I not correct with some of my assumptions ? <br><br>Thanks<br><br>Volker<br> <br><br><br><br><br>-- <br><br>_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/<br><br>Volker Schauer (Dipl.Phys)<br><br>Institute of Applied Mechanics (Civil Engineering), Chair 1<br>University of Stuttgart<br>Pfaffenwaldring 7<br>D-70569 Stuttgart<br>GERMANY<br><br>Phone ++49 (0)711-68560044<br>email: schauer@mechbau.uni-stuttgart.de<br><br><br>_______________________________________________<br>dune-pdelab mailing list<br>dune-pdelab@dune-project.org<br><a href="http://lists.dune-project.org/mailman/listinfo/dune-pdelab">http://lists.dune-project.org/mailman/listinfo/dune-pdelab</a><br></blockquote></body></html>