topic Re: Storing factorized matrix with MKL DSS in Intel® oneAPI Math Kernel Library

Storing factorized matrix with MKL DSS

gandalf85 — Wed, 15 Jul 2009 21:53:02 GMT

It seems that we have to call the MKL DSS functions in order in the same executable. After calling the factor command, is there a way to store the factored matrix in the same format as the matrix we send to it? I want to write this factored matrix to a file, then call solve on it later on. Also, can we send MKL DSS a zero-indexed matrix (so the top-left element is the (0,0) element)? Thanks alot.

Re: Storing factorized matrix with MKL DSS

jaewonj — Wed, 15 Jul 2009 22:46:57 GMT

Quoting - gandalf85

Also tried but found PARDISO (DSS) does not support this. We cannot extract a factorized matrix.

A workaround may be tostorethe internal data structure (void *pt[64]) or call pardiso with multiple right hand side.

I believe PARDISO only supports 1-based indexing.

Re: Storing factorized matrix with MKL DSS

gandalf85 — Thu, 16 Jul 2009 13:16:51 GMT

OK, thanks for the reply. I guess I don't need to store it in any particular format; I guess I can just store handle (I'm using strictly DSS and not calling paradiso directly). Is there some way to write the handle structure to a file so I can recover it later when I'm performing a solve? Another problem I see with that is that DSS seems to want to do things in a strict order (i.e. create->define->reorder->factor->solve), so would I be able to extract handle from a file then perform a solve immediately after? Thanks alot.

Re: Storing factorized matrix with MKL DSS

jaewonj — Thu, 16 Jul 2009 23:06:23 GMT

The void type pointer, _MKL_DSS_HANDLE_t,is like a black box.We arenot allowed to peek inside. Since we don't know what's inside, we'reunable to writethe handler to a file.

I think unless the author providesa function like GetFactorizedMatrix(), there's no way toextract this information. Other packages such as UMFPACK, CHOLMOD, and TAUCS all allowus to extract a factorized matrix, but I do not know why PARDISO (=DSS)does not support this,I guess maybe on purpose?

If there's a way to store a factorized matrix in any format, Ialso really want to know about it.