[SciPy-user] Least squares for sparse matrices?
Nils Wagner
nwagner at iam.uni-stuttgart.de
Fri Nov 21 13:43:10 EST 2008
On Fri, 21 Nov 2008 11:14:27 -0700
Andy Fraser <afraser at lanl.gov> wrote:
> I am trying to understand the behavior of matrices that
>approximate
> Radon transforms and their inverses. So far, I've used
>commands like
> the following to experiment with various values of
>SVDcond:
>
> V_1,resids,rank,s =
>numpy.linalg.lstsq(M_Radon,U_0,rcond=SVDcond)
>
> Is there a sparse version of lstsq that will let me
>exploit the
> sparseness of M_Radon?
>
> It would be even better if there were something like a
>sparse SVD that
> would let me pre-calculate an SVD decomposition and then
>later use it to
> invert several U_0 vectors.
>
> --
> Andy Fraser ISR-2 (MS:B244)
> afraser at lanl.gov Los Alamos National Laboratory
> 505 665 9448 Los Alamos, NM 87545
> ______________________
See
http://projects.scipy.org/scipy/scipy/ticket/330
Nils
More information about the SciPy-User
mailing list