[MOAB-dev] Issue with DataCoupler

[Andrei Shvarts]

Hello,

I am one of the core developers of MoFEM, for which MOAB is a backbone.

Recently, we have been looking for functionality to transfer data between meshes, and it appears that MOAB provides two options: Coupler and DataCoupler classes, the latter described as a more advanced version of the former.

As a starting point, we would need a constant projection from tags on elements in the source mesh to tags on elements in the target mesh. Coupler seems to handle this; however, we need to use 9-value tags (for stress tensors), while Coupler appears to support only scalar tags. We could store each stress component as a separate scalar tag and interpolate them individually, but this seems rather tedious, especially since the DataCoupler class appears to support multi-value tags.

However, I have been unable to transfer data from element tag to element tag using DataCoupler; the result is always zero. Even the datacoupler_test with the default meshes does not seem to work, as the resulting element tag values are all zero.

I ran the test with the following command:
./datacoupler_test -itag element_field -meth 0 -outfile out.h5m

I have compiled develop branch, commit f4c7a65af7cc9d520577877eeef39fd9e2493fde

Could you advise me please if I am using DataCoupler correctly?

Many thanks,
Kind regards,
Andrei

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Dr Andrei Shvarts
Lecturer – Infrastructure & Environment
Glasgow Computational Engineering Centre
James Watt School of Engineering
University of Glasgow