Turn on suggestions

Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for

- Intel Community
- Software
- Software Development SDKs and Libraries
- Intel® oneAPI Math Kernel Library
- How to use the pardiso for partial solution with correct iparm(31) value?

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Mute
- Printer Friendly Page

CHENG__JIM

Beginner

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

09-10-2019
02:36 AM

75 Views

How to use the pardiso for partial solution with correct iparm(31) value?

Dear All

I am testing the example given in the MKL manual for pardiso with partial solution in Fortran.

As stated for iparm(31), when its value is 3, selected components of the solution vectors will be computed. However, I tried many times, with different perm values, iparm(31) values(=1, 2 or 3), and paramater locations, it always give the whole solution.

Since for my real problem(with thousands of DOF), only a few elements in rhs are nonzero and only a few selected components of the solution are needed. I have to realize the partial solution function to cut the time cost.

I hope you can help me. Thanks a lot.

The attachment is my fortran code.

Jim Cheng

Link Copied

1 Reply

Kirill_V_Intel

Employee

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

09-16-2019
12:29 PM

75 Views

Hello Jim,

1) (minor) First, looking at your code I see

iparm(7) = 16 ! default logical fortran unit number for output

doesn't agree with Intel MKL documentation (iparm[7] is the output iparm parameter which can give the number of iterative refinement steps performed). Hence, the question is whether you're actually intend to use Intel MKL PARDISO or some other solver with a similar interface?

2) Second, you also have

iparm(8) = 9 ! numbers of iterative refinement steps

but the partial solve by its nature does not support iterative refinement. So, I believe due to this setting PARDISO actually performed a full solve.

Could you please switch this iparm off (set iparm(8)=1) and see what happens?

Hope this helps!

Best,

Kirill

Topic Options

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page

For more complete information about compiler optimizations, see our Optimization Notice.