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Re: matrix functions
From: |
Bård Skaflestad |
Subject: |
Re: matrix functions |
Date: |
Tue, 21 Dec 2010 16:58:18 +0100 |
On Tue, 2010-12-21 at 16:14 +0100, Bård Skaflestad wrote:
> On Tue, 2010-12-21 at 15:02 +0100, Jordi Gutiérrez Hermoso wrote:
> > On 21 December 2010 04:05, Bård Skaflestad <address@hidden> wrote:
> >
> > > I was about to suggest you use the 'funm' function, but now I see that
> > > 'funm' is only available (by default) in That Other Software. On the
> > > other hand, the 'linear-algebra' add-on package from OctaveForge does
> > > contain a 'funm' implementation.
> >
> > Huh, that's awkward, because the docstring for expm mentions funm,
> > which isn't included in core. I see the funm implementation is quite
> > naïve and relies on the matrix being diagonalisable.
>
> Naïve indeed. The implementation uses exactly the algorithm alluded to
> by the OP and, as you say, implements even this algorithm poorly. I
> almost feel like withdrawing my original reference to this particular
> function...
Oh, lest I forget: This has been extensively discussed in the mailing
list before. See, e.g., the thread entitled "logm robustness" from
April of this year (and a few similarly entitled follow-on threads).
Regards,
--
Bård Skaflestad <address@hidden>
SINTEF ICT, Applied Mathematics
- matrix functions, CdeMills, 2010/12/21
- Re: matrix functions, Bård Skaflestad, 2010/12/21
- Re: matrix functions, CdeMills, 2010/12/21
- Re: matrix functions, Jordi Gutiérrez Hermoso, 2010/12/21
- Re: matrix functions, Bård Skaflestad, 2010/12/21
- Re: matrix functions,
Bård Skaflestad <=
- Re: matrix functions, Philip Nienhuis, 2010/12/21
- Re: matrix functions, Jordi Gutiérrez Hermoso, 2010/12/22
- Re: matrix functions, Philip Nienhuis, 2010/12/22
- Re: matrix functions, Miroslaw Kwasniak, 2010/12/28
- Re: matrix functions, Jordi Gutiérrez Hermoso, 2010/12/28