[SciPy-user] Eigenvalues and eigenvectors

[David Grant]

On 7/11/06, Johannes Loehnert <a.u.r.e.l.i.a.n at gmx.net> wrote:
>
> Hi,
>
> > This probably isn't what you meant, but...
> > last I checked there was no function in Scipy that would let you get
> just
> > *some* eigenvalues and eigenvectors.  eig() gets you *all*
> eigenvals/vecs
> > whether you want them or not.   Which is really a bad idea if you're
> trying
> > to do some sort of eigenvector-based compression/dimension-reduction on
> a
> > 5000 dimensional dataset.
>
> scipy.linalg.eig_banded can be used to obtain a subset of eigenvectors (by
> giving limits for the eigenvalues or by specifying an index range).
> However
> it is only applicable to symmetric and hermitian matrices (preferably
> band-limited, of course). Internally it wraps the lapack routines dsbevx /
> zhbevx.
>
> I do not know if it is already contained in the latest scipy release,
> maybe
> you need to build from svn.
>

Thanks. It doesn't look like it is in scipy-0.4.9

-- 
David Grant
Please Note my new email address: davidgrant at gmail.com
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