[Dune] How to implement point to point communication

[Benedikt Oswald]

Dear Dune,

for ca. 3 months now we have been working to implement a higher order curvilinear grid manager,
using the concept of the metagrid on top of a host grid.

In particular, Aleksejs Fomins is in charge of this project within LSPR AG.

I should also mention that the sources of this project are publicly available on github
(clone of dune-geometry, dune-curvilineargrid)


The plan has been as follows:
=======================

1) implement the curvilinear geometry in the class LagrangeGeometry which handles
    the curvilinear, tetrahedral geometry using Lagrange polynomials

    we comment that at present we implement up to order 5 but in principle
    we can implement higher orders as well, if required.

    status: implemented & tested


2) use the concept of the meta grid, embodied in the GeometryGrid


3) after discussions with Peter Bastian, we decided to create a new Dune module,
    i.e.dune-curvilineargrid that uses sources from GeometryGrid which have been
    renamed to reflect the new module name; in particular, GeometryGrid in its
    present form simply does not do what is needed.

    We have decided to use the new dune-alugrid module as the host grid and
    we appreciate the ALUGrid effort very much.

    status: in progress


4) we wish to avoid the bottleneck of reading the whole mesh on the master node only
    and have therefore implement a parallel gmsh reader which reads the full curvilinear
    gmsh .msh format, including tags and everything

   status: operational


5) as a consequence, we need to repartition the mesh before we create the grid,both
    that is the reason why Aleksejs asked for advice on how to communicate elements
    between the MPI processes;  in fact, we have found a solution and use the well
    known CLINK protocol


6) as a result, we estimate that we will have a first version of the parallel dune-curviineargrid
    module operational in December; 

    the Dune community is very welcome to test it and comment on it.


We really appreciate the support given to us from the Dune mailing list and we appreciate
the Dune effort enormously. On the other hand, we openly admit that, sometimes in the past,
we perceived certain comments as a tad ‘grossfürstlich’.


with the best of intentions and wishes for a wonderful day,

Benedikt






--------------------------------------------------------------------------------------------------------------------------------------------------------------
Dr. sc. techn. Benedikt Oswald - first engineer - LSPR AG - phone - +41 43 366 90 74
Technoparkstrasse 1, CH-8005 Zürich, benedikt.oswald at lspr.ch - labor vincit omnia improbus
--------------------------------------------------------------------------------------------------------------------------------------------------------------


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 842 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <https://lists.dune-project.org/pipermail/dune/attachments/20141016/d2119e7d/attachment.sig>