[petsc-users] DMPlex: Mapping cells before and after partitioning

[Bisht, Gautam]

> On Jan 9, 2020, at 2:58 PM, Jed Brown <jed at jedbrown.org> wrote:
> 
> "'Bisht, Gautam' via tdycores-dev" <tdycores-dev at googlegroups.com> writes:
> 
>>> Do you need to rely on the element number, or would coordinates (of a
>>> centroid?) be sufficient for your purposes?  
>> 
>> I do need to rely on the element number.  In my case, I have a mapping file that remaps data from one grid onto another grid. Though I’m currently creating a hexahedron mesh, in the future I would be reading in an unstructured grid from a file for which I cannot rely on coordinates.
> 
> How does the mapping file work and how is it generated?

In CESM/E3SM, the mapping file is used to map fluxes or states between grids of two components (e.g. land & atmosphere). The mapping method can be conservative, nearest neighbor, bilinear, etc. While CESM/E3SM uses ESMF_RegridWeightGen to generate the mapping file, I’m using by own MATLAB script to create the mapping file.

I’m surprised that this is not an issue for other codes that are using DMPlex. E.g In PFLOTRAN, when a user creates a custom unstructured grid, they can specify material property for each grid cell. So, there should be a way to create a vectorscatter that will scatter material property read in the “application”-order (i.e. order before calling DMPlexDistribute() ) to ghosted-order (i.e. order after calling DMPlexDistribute()).


> We can locate points and create interpolation with unstructured grids.
> 
> -- 
> You received this message because you are subscribed to the Google Groups "tdycores-dev" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to tdycores-dev+unsubscribe at googlegroups.com.
> To view this discussion on the web visit https://protect2.fireeye.com/v1/url?k=b265c01b-eed0fed4-b265ea0e-0cc47adc5e60-1707adbf1790c7e4&q=1&e=0962f8e1-9155-4d9c-abdf-2b6481141cd0&u=https%3A%2F%2Fgroups.google.com%2Fd%2Fmsgid%2Ftdycores-dev%2F8736come4e.fsf%2540jedbrown.org.