geqp3

Petros_Mamales — Wed, 21 Nov 2012 15:43:30 GMT

Hi,

In the documentation for the QR decomposition with pivoting there is very little mention on how to obtain the Q and R matrices that result from the application of the function.

The one -somewhat suspicious- guideline, is to use the ogqr (real matrices) function.

However, this function is ignorant of the permutation vector.

Typically for the regular QR the input matrix is overwritten and the upper triangular part contains R and the lower contains info that allow for the extraction of Q - using ogqr.

So, how does it work now ? How does the pivoting info (i.e. column permutation) surfaces here ?

Thank you very much in advance,

Petros

PS: I am using MKL 10.3, Win7 and visual studio 2010 (i.e. c interface)

Update:

Petros_Mamales — Wed, 21 Nov 2012 17:02:58 GMT

Update: Apologies , for a moment I thought that orgqpr was mkl provided and not part of mkl. I think I am good now. Thank you, Petros

..and not part of LAPACK ! ;-

Petros_Mamales — Wed, 21 Nov 2012 17:15:28 GMT

..and not part of LAPACK ! ;-)

topic Update: in Intel® oneAPI Math Kernel Library

geqp3

Update:

..and not part of LAPACK ! ;-