Post-processing matrix

Main Forum
1

Hello!
I was wondering whether it was possible to extract the matrix of a linear post-processing step to construct the C matrix of a state space representation of the system.
E.g. I have the z magnetic vector potential as a primary solution, and would like to calculate x,y flux densities in certain points of the mesh.
Can I extract the matrix of this operation somehow, similarly to the bilinear form matrix and linear form vector?

Thanks,
KLK

2

Maybe the .ipynb file that Joachim attached here BlockMatrix Direct Solver may be of help. Sorry that I cannot be more helpful.