dolfin team mailing list archive

[Anne Voigt <anne.voigt@xxxxxxxxxxxxxxxxxxxxx>]

Thank you. I now try to write my own Tensor by deriving from the
GenericTensor class. Could you write me some information about the interface? 
Especially what the parameters of the function
GenericTensor::get(..) and GenericTensor::set(..) are? It is not clear
for me and I cannot find a documentation about it. 

Regards,
Anne

> > 
> > Am Montag, den 21.01.2008, 16:40 +0100 schrieb Anders Logg:
> > > On Sun, Jan 20, 2008 at 11:49:57AM +0100, Anne Voigt wrote:
> > > > -----Ursprüngliche Nachricht-----
> > > > Von: Ola Skavhaug [mailto:skavhaug@xxxxxxxxx] 
> > > > Gesendet: Freitag, 18. Januar 2008 23:53
> > > > An: Anne Voigt; dolfin-dev@xxxxxxxxxx
> > > > Betreff: Re: [DOLFIN-dev] assemebling process for a trilinearform
> > > > 
> > > > Anders Logg skrev den 18/01-2008 følgende:
> > > > > On Fri, Jan 18, 2008 at 03:56:46PM +0100, Anne Voigt wrote:
> > > > > > I just wanted to ask if there is any progress with the assembling
> > > > > > process of a trilinearform.
> > > > > > As a little reminder, here is what I wrote in December:
> > > > > > I have the following problem. I defined a trilinearform with the help of
> > > > > > FFC. Now I wanted to write the results into a 3D tensor which is
> > > > > > assembled with the help of assemble.h . What I already did I implemented
> > > > > > a subclass of GenericTensor called Tensor. But unfortunately I am still
> > > > > > not able to assemble such a tenor. The reason is
> > > > > > SparsityPatternBuilder.cpp which is not implemented for problems >2D:
> > > > > > 
> > > > > >  void SparsityPatternBuilder::build(SparsityPattern& sparsity_pattern,
> > > > > >  Mesh& mesh,
> > > > > >                     UFC& ufc)
> > > > > >  {
> > > > > >    if (ufc.form.rank() == 0)
> > > > > >      scalarBuild(sparsity_pattern);
> > > > > >     else if (ufc.form.rank() == 1)
> > > > > >      vectorBuild(sparsity_pattern, ufc);
> > > > > >    else if (ufc.form.rank() == 2)
> > > > > >     matrixBuild(sparsity_pattern, mesh, ufc);
> > > > > >    else
> > > > > >      error("Cannot compute sparsity patterm for size > 2.");
> > > > > >  }
> > > > > >  
> > > > > > I know that you all are very busy that's why I would be already pleased
> > > > > > if you would be able to tell how much longer I may have to wait?!
> > > > > > 
> > > > > > Thanks for your help
> > > > > > Anne
> > > > > > 
> > > > > > _______________________________________________
> > > > > > DOLFIN-dev mailing list
> > > > > > DOLFIN-dev@xxxxxxxxxx
> > > > > > http://www.fenics.org/mailman/listinfo/dolfin-dev
> > > > > 
> > > > > We're working on this. The hangup right now is to solve a problem
> > > > > related to circular dependencies between matrix classes and matrix
> > > > > factories (in particular for uBLAS where things are templated).
> > > > > 
> > > > > We may have found a solution today (in particular Martin who has a
> > > > > black belt in templates). Ola, did it work?
> > > > 
> > > > Sure, it did. I have to compile DOLFIN using PETSc for all the part to
> > > > fit together. I'll probably commit early next week.
> > > > 
> > > > Ola
> > > >  
> > > > 
> > > > Great news!!! Thanks to all of you. Now I can go ahead with my final
> > > > thesis!!! :-)
> > > > 
> > > > Anne
> > > 
> > > ok, it might be fixed now. Try and see if you can make it work.
> > > 
> > > What we've done (mostly Ola and Martin) is that we have added a method
> > > factory() to the interfaces. These should for each backend return a
> > > factory that knows how to create vectors and matrices, and sparsity
> > > patterns for that backend.
> > > 
> > > What you need to do to assemble into your own tensor is to implement
> > > your own tensor class (subclass of GenericTensor), your own factory
> > > (subclass of LinearAlgebraFactory) and your own sparsity pattern
> > > (subclass of GenericSparsityPattern).
> > > 
> > > The assembler will ask your tensor to return a factory and then it
> > > will ask that factory to create a sparsity pattern. Before assembling
> > > into your tensor, it will iterate over the elements and let you build
> > > the sparsity pattern. Depending on how you have implemented your
> > > tensor class, you may or may not want to actually build the sparsity
> > > pattern.
> > > 
> > > See if it works.
> > > 
> > 
>