dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

Kent Andre wrote:
> On ti., 2009-09-01 at 17:16 +0100, Garth N. Wells wrote:
> > Kent Andre wrote:
> > > Hi, 
> > > A.zero() is called both when reset_tensor is true and false
> > > in Assembler::init_global_tensor. 
> > >
> > > The code is as follows: 
> > >
> > > void Assembler::init_global_tensor(GenericTensor& A,
> > >                                    const Form& a,
> > >                                    UFC& ufc, bool reset_tensor)
> > > {
> > >   if (reset_tensor)
> > >   {
> > >     ... 
> > >   }
> > >   else 
> > >     A.zero();
> > > }
> > >
> > > Is this on purpose or is it a bug ? 
> > The code is correct. 'A.zero()' zeroes the entries but preserves the 
> > non-zero structure of the matrix.
> >
> > Garth
>
> Then maybe reset_sparsity_pattern is a better name ? 

We could extend the assembler interface to

  assemble(GenericTensor& A, const Form& a,
           bool reset_tensor_sparsity=true, bool add_values=false);

I'm not a big fan of booleans though because they make no sense to the 
reader in the calling code, e,g. what does

  assemble(A, a, true, true);

mean? We could use the parameter system instead.

Garth




> (I would like to not zero out the matrix before assembly, 
> but I guess I can do this by some backend-spesific code where
> I add the matrices together afterwords.) 
>
>
> Kent