How to access CreateSmoothingBlocks from python for fes?

Hello,

I am trying to use the "many" default smoothing blocks implemented for finite element spaces for preconditioning.
So I tried to export CreateSmoothingBlocks for a finite element space (EdgeFESpace is "exactly" your NedelecFESpace), with
But when I call python complains:
I didn't find a solution to this in the source files. Can you help with this?

Best,
Guosheng

This means that the class Table<int, unsigned long> doesn't have a Python equivalent (=export). You can either export the table or convert the table first to some Python object (for example a list of lists).
Best
Christopher

Yes. I noticed that the python list will then be converted back to Table <int, unsigned long> in the CreateBlockSmoother class.
But, I haven't found a way to convert the Table<int, ...> class back to python list back. I don't know how to create a python list in C++.

Something like should work.

But you could as well just export the Table and write another python constructor for the smoother to be constructed with a table, then you don't have to copy

Best

Thanks, Christopher. This works.
I need to change the loop to as table is a smart pointer from CreateSmoothingBlocks.

The code works much faster now.
So, there is basically no difference from the python end whether the block is a list of lists or a list of sets (which we use to generate the blocks in the python script) because they will simply be converted to the Table<int> type in CreateBlockSmoother, right?

To create a new python BlockSmoother constructor that takes the table as input seems the fastest approach, but then I need to modify the source file in linalg/python_linalg.cpp, which is a bit of a headache for me. (if you could include this in later ngsolve versions, that would be great

Currently I am simply adding "new" fespaces/classes in a separate project, which I feel a little bit safer as I don't need to directly touch the git source files.