There is now a patch available for the original suggestion that graph
eigenvalues could be improved. In the course of doing this, I
discovered that any eigenvalue of a graph was having its complex part
stripped off. Presumably, this was to clean up annoying nearly-zero
complex parts for graphs (
2009/6/13 Rob Beezer :
>
> On Jun 12, 1:17 am, John Cremona wrote:
>> I think there's a case for having a more basic class for holding
>> "things with multiplicities"; the the spectrum could be one of these
>> (or a class derived from it) and Factorization would also be a derived
>> class.
>
> H
On Jun 12, 1:17 am, John Cremona wrote:
> I think there's a case for having a more basic class for holding
> "things with multiplicities"; the the spectrum could be one of these
> (or a class derived from it) and Factorization would also be a derived
> class.
Hi John,
Yes, I agree. There's a
On Fri, Jun 12, 2009 at 09:17:29AM +0100, John Cremona wrote:
>
> 2009/6/12 Rob Beezer :
> >
> > Hi John,
> >
> > Thanks for the reply, the suggestions and the examples. I've seen the
> > Factorization object and briefly thought of building a Spectrum
> > object, but thought it sounded like over
2009/6/12 Rob Beezer :
>
> Hi John,
>
> Thanks for the reply, the suggestions and the examples. I've seen the
> Factorization object and briefly thought of building a Spectrum
> object, but thought it sounded like overkill. But maybe I can just
> subclass Factorization and override the _repr_ me
Hi John,
Thanks for the reply, the suggestions and the examples. I've seen the
Factorization object and briefly thought of building a Spectrum
object, but thought it sounded like overkill. But maybe I can just
subclass Factorization and override the _repr_ method (or similar) to
print the spect
2009/6/11 Rob Beezer :
>
> On Jun 8, 7:47 pm, Jason Grout wrote:
>> I've never had to use the left eigenvectors of a graph.
>
> And I've never needed a directed graph so my matrices are always
> symmetric. (Just kidding.) ;-)
>
> The above is now: http://trac.sagemath.org/sage_trac/ticket/6258
On Jun 8, 7:47 pm, Jason Grout wrote:
> I've never had to use the left eigenvectors of a graph.
And I've never needed a directed graph so my matrices are always
symmetric. (Just kidding.) ;-)
The above is now: http://trac.sagemath.org/sage_trac/ticket/6258
A related question: matrices and
Rob Beezer wrote:
> Currently, eigenspaces of graphs are computed by constructing the
> adjacency matrix, then converting to a matrix over RDF, and finally
> computing the eigenspaces of this matrix. When the graph has integer
> eigenvalues of high multiplicity, numerical inaccuracy is leading to
