Subject: Help with very very slow determinant calcuation
From: Claudio Delpino
Date: Sat, 6 Aug 2011 06:25:20 -0300
Is there any reason you're not factorizing the matrix ?
2011/8/6 Bernard Hurley <bernard at marcade.biz>
> On Wed, 2011-08-03 at 19:26 -0700, Nghia Ho wrote:
> > Hi all,
> >
> >
> > I'm trying to run the determinant() function a 10x10 matrix that
> contains all symbolic values. I've searched through the mailing list to find
> a solution. I've tried ratmax:true and newdet(), but it is still taking
> forever. In fact, as of writing now it has been going for over 12 hours and
> still hasn't finished! Is the determinant doing other stuff besides doing
> the multiplication and addition? Is it trying to simplify/factorise as it
> goes along?
> >
> > Nghia
> >
> > _______________________________________________
>
> To evaluate a 10x10 determinant containing independent symbols requires
> 10! = 3628800 multiplications, as well as additions etc. I would expect
> this to take a very very long time. There are ways of cutting down on
> this in a numerical matrix or if there are relationships between the
> symbols.
>
> Bernard.
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