Hi Nicolas,

If what you want is their physical locations then you can create a P2 VectorFunctionSpace and interpolate the mesh coordinates into it. This will give you the physical locations of the P2 point evaluation nodes in the same order they are used in the assembled matrix.

Cheers,

David

From: <firedrake-bounces@imperial.ac.uk> on behalf of Karin&NiKo <niko.karin@gmail.com>
Date: Tuesday, 25 August 2020 at 13:02
To: firedrake <firedrake@imperial.ac.uk>
Subject: [firedrake] retrieve dof and entities of assembled matrix entries

Dear Firedrakers,

I wonder how to retrieve the dof and support entities of the entries of an assembled matrix. To make it clearer, let's say I consider a simple elasticity problem that I discretize with P2 elements. I would like to know which nodes and degrees of freedom the values of the assembly matrix refer to.

Best regards,

Nicolas