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
- solving underdetermined system and LAPACKE_dormqr error

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

Azua_Garcia__Giovann

Beginner

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

03-30-2012
10:46 AM

66 Views

solving underdetermined system and LAPACKE_dormqr error

Trying to do the same as in Matlab (snippet below) but using MKL produces at the point of doing the Q'*b with LAPACKE_dormqr "MKL ERROR: Parameter 10 (ldb) was incorrect on entry to cblas_dtrsm". Is it a valid case trying to solve underdetermined systems with MKL? I know this doesn't make a lot of sense i.e. infinite solutions but Matlab is quite robust in that respect.

I managed to get the append column QR update bit working green unit tests yippiiiii :) and this underdetermined system was a border case test which results in the MKL error above.

Thanks in advance,

Best regards,

Giovanni

>> A =[9.572000e-01 1.419000e-01 7.922000e-01 3.570000e-02 6.555000e-01;

4.854000e-01 4.218000e-01 9.595000e-01 8.491000e-01 1.712000e-01;

8.003000e-01 9.157000e-01 6.557000e-01 9.340000e-01 7.060000e-01]

A =

0.9572 0.1419 0.7922 0.0357 0.6555

0.4854 0.4218 0.9595 0.8491 0.1712

0.8003 0.9157 0.6557 0.9340 0.7060

>> b = [0.0318; 0.2769; 0.0462]

b =

0.0318

0.2769

0.0462

>> A\\b

ans =

0

0

0.2745

0.0739

-0.2872

Link Copied

1 Reply

mecej4

Black Belt

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

03-30-2012
03:41 PM

66 Views

pinv(A)*b

There is an example, dgelqfx.f, and associated input data dgelqfx.d, in the MKL examples/lapack directory. With this code, but your data above, I get the minimum norm solution as

-0.0540

-0.0954

0.2668

0.1395

-0.1821

which agrees with the result from the Matlab calculation pinv(A)*b.

If you want help with a problem with calling MKL, at a minimum you have to show the routine invocation and the declarations of the routine arguments. It would be better to post a complete example, if feasible.

- 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.