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Fixing RGDSW coarse space for irregular domain decompositions

James Willenbring requested to merge searhein:fix-rgdsw-2 into develop

Created by: searhein



For certain irregular domain decompositions, the previous implementation of the RGDSW coarse space did not yield a correct partition of unity on the domain decomposition interface. This was resolved by introducing a new hierarchy of the domain decomposition interface components. Based on the framework of ancestors and offspring, as described in

On the Design of Small Coarse Spaces for Domain Decomposition Algorithms Clark R. Dohrmann and Olof B. Widlund SIAM Journal on Scientific Computing 2017 39:4, A1466-A1488

In the process, many functions related to the DDInterface class had to be modified.

This should clearly improve the performance for the corresponding critical cases.

How Has This Been Tested?

All tests in FROSch pass the ctest. Furthermore, we obtained a partition of unity on the domain decomposition interface for various domain decompositions (even those which were problematic before) using our in-house finite element code.


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  • All new and existing tests passed.
  • No new compiler warnings were introduced.
  • These changes break backwards compatibility.

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