yade-users team mailing list archive

[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>]

> > We will experiment, thank you for the tip. I'm not so sure a lot of 
> > algebra libraries with parallel features are available.
> There is PLENTY! At least those oofem uses are 
> http://glaros.dtc.umn.edu/gkhome/metis/parmetis/overview and

Hehe, I know there are plenty, but Metis is a preconditionner, not a 
solver, and in fact taucs is using Metis. ;-)
I compiled taucs and linked it with the last version of metis. And yes, 
it works well, but metis is not the fastest preconditionning method for 
our matrices (in single thread at least).
Taucs is actually linking with some of the libraries you see everywhere 
in algebra web pages (blas, lapack, metis, atlas).

> http://www.mcs.anl.gov/petsc/petsc-2/, which are damn good as far as I 
> know (see also 
> http://www.mcs.anl.gov/petsc/petsc-2/miscellaneous/external.html).
We can't use fem/fvolumes and such codes out of the box because we are 
assembling our won matrice in a non-traditional way.
If we use such programms, it is only by calling low level functions, 
which in many cases means using taucs...

I saw one interesting thing in miscellaneous/external, though :

http://www.cs.utexas.edu/users/plapack/

taucs is based on lapack, but I don't think it uses plapack. plapack 
will be something to consider perhaps.
Thanks.



Bruno



> > > Oh, BTW, is there agreement on having useShear by default and
> > > progressively remove prevNormal from various InteractionPhysics 
> > > classes?
> > I'd prefer to keep the traditional (Cundall) incremental form for 
> > now. The equations are simpler, especially in 3D, so it is easier to 
> > understand what happens and implement different laws. I will change 
> > my mind one day perhaps, but for now I feel like the incremental form 
> > is good enough for dry friction. :)
> Ah, nay, there is still misunderstanding here. Read 
> SpheresContactGeometry::updateShear and compare it to 
> updateShearForce. It is the _same_ incremental formulation, but it 
> increments shear _displacement_ (rather than _force_), which is, I 
> think, what most constitutive laws need (even if they are non-linear) 
> and therefore can use. I would like to have that incremental formulas 
> at one place only. (The non-incremental algo is in Dem3Dof* classes 
> and I am quite happy with it.)
Oh ok. So, no problem.
Bruno

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Chareyre Bruno
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