[petsc-dev] questions on new include organization

[Barry Smith]

On Feb 12, 2013, at 11:17 PM, Matthew Knepley <knepley at gmail.com> wrote:

>    Regardless of these two, PetscSection does not belong in the vector subdirectory and most definitely not  in the impls/seq directory, so even if in the end it does not become exactly an IS it more belongs in the is directory then in the vec directory
> 
> That is convincing.
>  
> > c) I believe the claim will be, "I can always think of the output as a list of integers", however that is a very broad category,
> >     which also includes graphs, meshes, etc. Internally this looks nothing like a list of numbers, and the current queries
> >     do not just return members of this list.
> 
>    a graph and mesh most definitely cannot be thought of as a list of integers since they contain information about relationships BETWEEN items. Does PetscSection contain such additional information?
> 
> Yes. PetscSection represents groups of numbers, and you can see the grouping.
>  
>    What queries "do not just return members of this list" in PETSc section? (That is queries we wish to retain anyways).
> 
> For example, you can ask "how many items are in group p?". This is crucial, and the whole point of the structure.
> I don't see how you can recover that information from just the list of dof numbers.

  Then a PetscSection is a collection of lists of integers. An IS is a single list of integers. So let's make IS be a collection of lists of integers (what was previously a PetscSection) and the current use of IS becomes a special case.

   Barry

> 
>     Matt
>  
> 
>    Barry
> 
> >
> >    Matt
> >
> >
> > 2) matimpl.h really needs vecimpl.h?
> >
> > #define __MATIMPL_H
> >
> > #include <petscmat.h>
> > #include <petsc-private/petscimpl.h>
> > #include <petsc-private/vecimpl.h>
> >
> > Doesn't seem to so I've removed the vecimpl.h and pushed
> >
> > Seems there may be a few of these unneeded dependencies hanging around, I'll try to hunt them down.
> >
> >    Barry
> >
> >
> >
> >
> > --
> > What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
> > -- Norbert Wiener
> 
> 
> 
> 
> -- 
> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
> -- Norbert Wiener