Hello, I have a FullMatrix A on which I'd like to perform a QR factorization and then access a few columns of the resulting orthogonal matrix Q. In looking for some internal options within deal.II, I came across the Householder class. After taking a pass at the source, it looks like the class has an optimized approach to storing information about the QR factorization in the form of a single full matrix and a diagonal vector. However, in looking at how the decomposition is being computed and how the least squares problem is being solved, I haven't been immediately able to tell how I might go about constructing Q from the information stored after initialize has run in the Householder object. I may have missed something and the Householder (full matrix) object does indeed simply store Q, but it seems it might be doing something different/optimized.
In any case, I'm simply looking for some advice as to how one might construct (or extract) Q from the Householder object. Thank you in advance for the help. Best, David -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
