Iterative solver (again) [Was: Re: [ODE] Russ' plans forODE?]

[Antonio_Martini at scee.net]

>Yes, I'm talking about something similar to that. Though if you are not
>running massively parallel (as GPU has to), you can just use Gauss-Seidel.
>But those are all just fancy-words. It is same as Jacobi, just meaning
that
>you immediatelly use available results.
methods can only be coupled, like a mixed Jacobi/Gauss-Seidel in that case
you may trade-off between parallelism and speed of convergence.

however as we well know from the theory of iterative linear system solvers,
for large systems a method based around the biconjugate gradient
method(Mendoza,Laugier, etc..) will
be faster. At least theoretically, given that simpler methods usually lead
to a more efficient implementation.







"Alen Ladavac" <alenl-ml at croteam.com>@q12.org on 27/04/2004 14:07:27

Sent by:    ode-bounces at q12.org


To:    "Nguyen Binh" <ngbinh at glassegg.com>, <Antonio_Martini at scee.net>
cc:    ODE at q12.org
Subject:    Re: Re[2]: Iterative solver (again) [Was: Re: [ODE] Russ' plans
       forODE?]


> you may me interested in:
>
> http://www.shaderx2.com/shaderx.PDF
>
> where a projected Jacobi method is mentioned.

Yes, I'm talking about something similar to that. Though if you are not
running massively parallel (as GPU has to), you can just use Gauss-Seidel.
But those are all just fancy-words. It is same as Jacobi, just meaning that
you immediatelly use available results.

> http://vcg.isti.cnr.it/people/vcgpeople/mendoza/jnrr.pdf
>
> if you look carefully the first jacobi iteration started with force=0 is
the same as step fast where off diagonal elements disappear. so it looks
> like that step fast is like running the first iteration, setting the
force
to zero and running the first iteration again.

I believe that Mendoza uses biconjugate gradient method, but other than
that, yes, it is very similar. And it's exactly what my recent objection to
stepfast was - it does only the first iteration.

Alen

_______________________________________________
ODE mailing list
ODE at q12.org
 http://q12.org/mailman/listinfo/ode








**********************************************************************
This email and any files transmitted with it are confidential and
intended solely for the use of the individual or entity to whom they
are addressed. If you have received this email in error please notify
postmaster at scee.net

This footnote also confirms that this email message has been checked
for all known viruses.

**********************************************************************
 SCEE 2004