topic Re:How to extract information of D matrix after LDLT decomposition in pardiso matrix? in Intel® oneAPI Math Kernel Library

How to extract information of D matrix after LDLT decomposition in pardiso matrix?

NEROKAI — Mon, 09 May 2022 09:01:03 GMT

Hello！

I want to extract the D matrix information in the LDLT decomposition in pardiso, using this method in order to use the strum sequence. I found the pardiso_sym_getdiag.c program in the example, mistakenly thought it was used to extract D matrix information, and compared it with MATLAB after using it. The results of this program are different, and even the information of negative numbers in the D matrix is different. If I want to extract the D matrix, what method should I use?

thanks for your help！

KAI

Re: How to extract information of D matrix after LDLT decomposition in pardiso matrix?

ShanmukhS_Intel — Wed, 11 May 2022 16:50:27 GMT

Hi,

Thanks for posting on Intel Communities.

>>If I want to extract the D matrix, what method should I use?

pardiso_getdiag method returns the diagonal elements of initial and factorized matrix.

In order to use this routine, make sure to set iparm[55] to 1 before the main pardiso loop.

Please find the below link for more details regarding the usage of pardiso_getdiag.

https://www.intel.com/content/www/us/en/develop/documentation/onemkl-developer-reference-c/top/sparse-solver-routines/onemkl-pardiso-parallel-direct-sparse-solver-iface/pardiso-getdiag.html

Best Regards,

Shanmukh.SS

Re: How to extract information of D matrix after LDLT decomposition in pardiso matrix?

ShanmukhS_Intel — Fri, 20 May 2022 03:36:37 GMT

Hi,

Reminder:

Has the solution provided helped? Is your issue resolved?

Kindly let us know if we could close this thread at our end.

Best Regards,

Shanmukh.SS

Re:How to extract information of D matrix after LDLT decomposition in pardiso matrix?

ShanmukhS_Intel — Fri, 27 May 2022 03:49:04 GMT

Hi,

We assume that your issue is resolved, If you need any additional information, please post a new question as this thread will no longer be monitored by Intel.

Best Regards,

Shanmukh.SS