[petsc-users] DMPlex global to natural ordering

[Danyang Su]

Dear All,

My simulation needs to pass initial condition from external file to the 
code. The initial condition in the external file is given in the natural 
ordering, which is consistent with the original input mesh file in VTK 
format. In the previous development, I use label to save all the local 
vertex numbering to global natural numbering. The code works, but it is 
not efficient in DMPlexDistribute when the mesh size is increased with a 
huge number of different labels.

I am looking for a more efficient way to pass the natural ordering data 
and let each processor read the local owned data (either with or without 
ghost nodes). I am trying to use DMPlexGetGlobalToNaturalSF and generate 
local node index to global natural node index. Due to my lack of 
knowledge about graph theory, I am a bit lost. Is there any example 
available to do this?

Thanks,

Danyang