Created attachment 507 [details]
patch for UmfPackSupport.h
UmfPackLU allows to perform factorizations where the matrix is singular, although this factorization cannot be used to solve linear systems, the LU factorization is still valid.
umfpack_numeric can return the status:
Which is a successful factorization (from umfpack manual):
"UMFPACK_WARNING_singular_matrix: Numeric factorization was successful, but the matrix is singular"
It would be nice to access this return status so that the LU factorization could still be used. For instance, I would need this to use the LU factorization for a nullspace basis evaluation.
It would also be interesting to see/change the default settings of umfpack.
I have attached a patch that would add these features.
Pushed after some minor renaming: