Re: [ublas] Computing sparse A'A

From: Gunter Winkler (guwi17_at_[hidden])
Date: 2007-02-13 16:56:41

Am Dienstag, 13. Februar 2007 17:32 schrieb Karl Meerbergen:
> True. But you need a sparse QR factorization. It exists, but I do not
> recall precisely where you can find code. A sparse QR can be done
> with a sparse Gram-Schmidt routine. Needless to say that fill-in is
> going to grow. Developing an efficient code using BLAS 3 etc is quite
> a job.

IMHO a sparse qr is already available from Tim Davis (UMFPACK&CSPARSE):

http://www.cise.ufl.edu/research/sparse/CSparse/ (see Chapter 5)

I thought it was already included in umfpack, isn't it?

mfg
Gunter