Inversion of a SumMatrix

NGSolve
1

I am wondering for the matrix type SumMatrix, do we have a way to take inversion?

For example, I have
hat = A.mat - B.mat@M.mat.Inverse(fesQ.FreeDofs(),inverse=“umfpack”)@B.mat.T

Do we have
“hat.Inverse”?

Thank you!

2

Which method do you want to use for the inverse? I see two black-box possibilities:

  • Use an iterative solver (CGSolver)
  • Convert the sum to a dense matrix (hat.ToDense()), and use a dense inverse

Don’t know if you like any of them. H-matrices could be nice option, but not available, currently.

3

Thanks for your response. I prefer to convert the sum to a dense matrix and use a dense inverse. I will try and update later.