Issue with intel pardiso (oneapi mkl)

[a_piquet]

Hello,

I'm trying to use the pardiso solver for my code so I tested some example and the results given by those test are wrong.

I have tested this file (which comes from the MKL example database) :

https://github.com/ww382/CS5220FinalProject/blob/master/pardiso_sym_c.c

This file solve the Ax=b equation with A a sparse matrix (8x8). So at the end I can check the answer given by Pardiso (x) by multiplying A*x and this does not give b ==> A*xpardiso /= b

I have also used Matlab to check the results (x=A\b) and the result is not the same than given by Pardiso.

The pardiso_sym_c.c file is compiled with OneAPI 2023 using :

icc pardiso_sym_c.c -lmkl_sequential -lmkl_core -lmkl_intel_lp64

Is there something I don't do correctly?

Thank you

A =

7. 0. 1. 0. 0. 2. 7. 0.
0. -4. 8. 0. 2. 0. 0. 0.
0. 0. 1. 0. 0. 0. 0. 5.
0. 0. 0. 7. 0. 0. 9. 0.
0. 0. 0. 0. 5. 1. 5. 0.
0. 0. 0. 0. 0. -1. 0. 5.
0. 0. 0. 0. 0. 0. 11. 0.
0. 0. 0. 0. 0. 0. 0. 5.

b =

1.
1.
1.
1.
1.
1.
1.
1.

A\b (from matlab) =  0.0519481
-0.1954545
0.
0.0259740
0.1090909
5.551D-17
0.0909091
0.2

while Pardiso give me :

xpardiso=

-0.041860

-0.003413

 0.117250

-0.112640

 0.024172

-0.107633

 0.198720

 0.190383

[a_piquet]

Strange, 

When i change the matrix mtype from "Real symmetric matrix" to "real and nonsymmetric", it works. The matrix is symmetric though so...

//MKL_INT mtype = -2;
MKL_INT mtype = 11;

[a_piquet · Accepted solution]

My bad, the matrix is symmetric so I miss the other part of the symmetry to compute my array... No problem in pardiso

You can close the thread. Sorry.

[ShanmukhS_Intel]

Hi Arthur,

Thanks for posting in Intel Communities.

It’s great to know that the issue has been resolved, in case you run into any other issues please feel free to create a new thread.

Best Regards,

Shanmukh.SS