[SciPy-User] permutation matrix in LU decomposition

Ralf Gommers ralf.gommers@gmail....
Wed Nov 28 14:35:48 CST 2012


On Wed, Nov 28, 2012 at 9:31 PM, Jason Grout <jason-sage@creativetrax.com>wrote:

> On 11/28/12 2:00 PM, Ralf Gommers wrote:
> >
> >
> >
> > On Mon, Nov 26, 2012 at 6:21 PM, Jason Grout
> > <jason-sage@creativetrax.com <mailto:jason-sage@creativetrax.com>>
> wrote:
> >
> >     I just noticed that the permutation matrix P returned in scipy's LU
> >     decomposition is the inverse (i.e., transpose) of the permutation
> matrix
> >     returned from Matlab's LU function.  In scipy, A = PLU, but in
> Matlab,
> >     PA=LU [1].  It's just a convention, of course, but perhaps a note
> about
> >     this could be added to the relevant table row of
> >     http://www.scipy.org/NumPy_for_Matlab_Users?
> >
> >
> > Sure, done. Note that that page is a wiki, so feel free to make more
> > updates.
>
> I just tried tweaking it a bit, and got this error when I tried to
> submit my edits:
>
> [Errno 31] Too many links:
> '/home/scipy/wiki/data/pages/JasonGrout(2f)MoinEditorBackup'
>
> See http://sage.math.washington.edu/home/jason/numpywikierror.html for
> more debugging output.
>

Seen that before, I think it's an intermittent error. I just managed to
save the same page again.

Ralf
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.scipy.org/pipermail/scipy-user/attachments/20121128/620e7247/attachment-0001.html 


More information about the SciPy-User mailing list