[petsc-users] using DM constructs

[Manav Bhatia]

Hi, 

   I am new to the DM constructs. I am curious if there is a compelling reason to move from handling IS sets to DM data structures. 

   My applications are built on top of libMesh. They used IS sets for a long time, and in recent years I have seen DM constructs in the library. However, I do not know why this is beneficial or necessary. The Petsc manual discusses DMDA for structured mesh, and I see reference to DMForest in the code (for unstructured mesh?) which is not discussed in the manual. 

   Is there a document that might provide the necessary background for DM and how best to derive from it, like in the libMesh source? 

   Any guidance would be appreciated. 

Regards,
Manav