Schur complement computation MKL_PARDISO

[Paolo98]

Hello,

I need to compute the Schur complement of a certain matrix K in the scope of domain decompositions for finite element applications. Given K as:

K = [K11 K12;
        K21 K22]

The Schur complement given by: S = K22 - K21 * K11^(-1) * K12

Using PARDISO, I am able to extract S calling pardiso_export as illustrated in a provided example (https://www.intel.com/content/www/us/en/docs/onemkl/developer-reference-c/2023-0/pardiso-export.html), but I would like to extract the factorization of K11 since I need it in following computations related to the domain decomposition. It is possible to extract it, or it is necessary to factorize K11 again?

Thanks in advance,

Paolo

[Fengrui · Accepted solution]

Hi Paolo,

I'm afraid the factors of K11 are not accessible using oneMKL Pardiso.

Best,

Fengrui