[petsc-users] Problem Setup / Multiple DAs

[Paul Urbanczyk]

Hello,

I'm relatively new to PETSc, so please forgive me if this is an obvious 
question.

For context, I am working on a single-block, structured, parallel CFD 
solver using sixth-order compact Pade schemes.

As I read through the manual and materials, it seems that using a 
"distributed array" (DA) would be extremely helpful in this case.

When I set up the DA for solution of the Navier-Stokes equations, it 
makes sense to set it up with five degrees of freedom (DoFs) to handle 
the five conservation equations.

However, there are a number of other calculations that need to be made 
(calculation of non-uniform mesh metrics, for example) that do not 
involve five DoFs.

Is there a way to handle varying numbers of DoFs with the same 
distributed array, or would it be better to use multiple DAs (one with 
five DoFs, one with a single DoF, etc) for different aspects of the problem?

Thanks for any/all advice on this matter!

-Paul