Extracting the interaction matrix (or) the Green's Functions from the MoM solution

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1

Hello,

I’m an undergraduate student trying to further my understanding of MoM and numerical electromagnetics and I would like to manipulate the underlying interaction matrix of structures I’m simulating in bempp to take out and add contributing Green’s functions to analyze the impact on the overall scattering response.

As I understand it, MoM solves for the interaction matrix, inverts it and then excites it with voltages and solves it for the currents. I’d like to access the underlying interaction matrix and manipulate it externally to bempp.

The interaction matrix I assume would be of size N x N, where N would be the number of meshes.

Please let me know how I can go about this. Thanks a lot!

2

Hello,

You can access the interaction matrix of the MoM with the function bempp.api.as_matrix(), see bempp_cl.api — Bempp 0.4.2 documentation.

For example, use matrix = bempp_cl.api.as_matrix(operator.weak_form()), with operator a boundary integral operator.

The size of the matrix depends on the formulation and function spaces you use. For RWG functions, this would be the number of edges in the triangular surface mesh.

Good luck.

Elwin

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