Update easi python script

[Thomas-Ulrich]

• Allows script to be used on volume data too (e.g. to compute rho Vs Vp).
• Add subdivide option for higher resolution model parameter evaluation.
• Some IA guided code improvement.

(tested on fault, volume output with and without refinement)

[NicoSchlw]

Thanks for the PR, it's a very valuable extension of the script!

The current script fails when using a seissol output xdmf without fault-tag or group. I would suggest to extend ReadFaultTagOrRegion to generate dummy tags (e.g., tags = np.ones(centers.shape[0])) when the respective fields are not present.

[NicoSchlw]

Thanks for addressing the review. I just tested that --subdivide_level 1 fails for volume data with AttributeError: 'UnstructuredGrid' object has no attribute 'GetFaces'

This fixes the issue for me:

            if self.is_volume:
                self.connect = mesh.cells.reshape(-1, n)[:, 1:n].astype(np.int64)
            else:
                self.connect = mesh.faces.reshape(-1, n)[:, 1:n].astype(np.int64)

Also, could you add a comment, what --subdivide_level 1,2 does?

[Thomas-Ulrich]

Thank you again for your tests. It should work now.

[NicoSchlw]

Thanks, LGTM now.

[davschneller]

(just forgot; in case it's relevant: SeisSol/Meshing#58 would move everything preprocessing script-related to the meshing/preprocessing repository)