dolfin team mailing list archive

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

Anders Logg wrote:
> On Tue, Sep 08, 2009 at 03:25:39PM +0200, Johan Hake wrote:
> > On Tuesday 08 September 2009 15:19:42 Garth N. Wells wrote:
> > > Johan Hake wrote:
> > > > On Tuesday 08 September 2009 12:58:41 Anders Logg wrote:
> > > > > On Tue, Sep 08, 2009 at 12:54:01PM +0200, Garth N. Wells wrote:
> > > > > > DOLFIN wrote:
> > > > > > > One or more new changesets pushed to the primary dolfin repository.
> > > > > > > A short summary of the last three changesets is included below.
> > > > > > >
> > > > > > > changeset:   6975:37efb9fe9fe684b23521574a89048705a9a0bc6e
> > > > > > > tag:         tip
> > > > > > > parent:      6974:6c4c77900222f82b7b32888b29a08fef9ddc5789
> > > > > > > parent:      6973:abda55b5dfa2b2d0fbe2614b15483911ef661fdc
> > > > > > > user:        Anders Logg <logg@xxxxxxxxx>
> > > > > > > date:        Tue Sep 08 12:51:01 2009 +0200
> > > > > > > files:
> > > > > > > description:
> > > > > > > merge
> > > > > > >
> > > > > > >
> > > > > > > changeset:   6974:6c4c77900222f82b7b32888b29a08fef9ddc5789
> > > > > > > parent:      6970:5d7fc35d3e597db508a005826efacb8dea6a00d9
> > > > > > > user:        Anders Logg <logg@xxxxxxxxx>
> > > > > > > date:        Tue Sep 08 12:01:43 2009 +0200
> > > > > > > files:       dolfin/fem/DofMap.cpp dolfin/fem/DofMap.h
> > > > > > > description:
> > > > > > > Make tabulate_facet_dofs accessible without having a ufc::cell, which
> > > > > > > makes it easy to access using iterators in Python.
> > > > > > Can we remove the version that takes a ufc::cell?
> > > > > Yes. Perhaps we should remove all the direct wrappers for UFC stuff
> > > > > and add a member function to return the underlying UFC object?
> > > > >
> > > > >   const ufc::dof_map& ufc_dof_map() const;
> > > > Should this be a member function of dolfin::DofMap? If so, it might be
> > > > sufficient with
> > > >
> > > >   const ufc::dof_map& ufc() const;
> > > Definitely not! The whole point of DofMap is to not expose ufc::dof_map
> > > in DOLFIN. It took a lot of work some time ago to fix this. Using
> > > ufc:dof_map screws up any dof renumbering.
>
> There shouldn't be any problem allowing access to the underlying UFC
> objects. We do the same thing for PETSc with mat() and vec() and a
> user has just as big a chance to screw things up there.

The problem with ufc objects is that developers screw things up too. 
I've spent a lot of time fixing this. Permitting access to the 
ufc::dof_map through DofMap defeats the purpose of having DofMap. I 
can't see any reason for allowing access to the ufc::dof_map from DofMap.

Garth

> --
> Anders
>
>
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