dolfin team mailing list archive

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

Johan Hake wrote:
> On Friday 13 March 2009 10:14:08 Garth N. Wells wrote:
> > Johan Hake wrote:
> > > On Thursday 12 March 2009 23:16:11 Anders Logg wrote:
> > > > On Thu, Mar 12, 2009 at 10:07:13PM +0000, Garth N. Wells wrote:
> > > > > Kristian Valen-Sendstad wrote:
> > > > > > > On Thu, March 12, 2009 14:25, Kristian Valen-Sendstad wrote:
> > > > > > > > Hi,
> > > > > > > > There seems to be a bug in the periodic boundary conditions demo
> > > > > > > > located in
> > > > > > > > /demo/pde/periodic/.
> > > > > > > >
> > > > > > > > It does not do what one would expect, and there are lots of "PETSC
> > > > > > > > ERROR"s
> > > > > > > > in both python and cpp.
> > > > > > > Do you use the latest development version? If so, I think you have
> > > > > > > the same problems as the buildbot.
> > > > > > >
> > > > > > > Johannes
> > > > > > Yes, I do.
> > > > > > However, Johan Elon Hake came to the rescue and set the linear algebra
> > > > > > backend to uBLAS, which solved the problem.
> > > > > It would be nice to figure out what the cause of the problem is with
> > > > > PETSc. What are the first few lines of the error message?
> > > > >
> > > > > Garth
> > > > I get the same thing on my machine and I guess everyone does:
> > > >
> > > >   Applying periodic boundary conditions to linear system.
> > > >   [0]PETSC ERROR: --------------------- Error Message
> > > >   ------------------------------------
> > > >   [0]PETSC ERROR: Object is in wrong state!
> > > >   [0]PETSC ERROR: Not for unassembled matrix!
> > > >
> > > > The problem is most likely a mix of calling A.ident(), getrow() and
> > > > not appropriately calling apply(). It should be fairly easy to fix but
> > > > I haven't had time to track it down.
> > > The problem started after Olas last push. Strange that a changeset that
> > > only affect XML files should have any to say for the PETSc backend?
> > apply() doesn't do anything for the uBLAS backend as there is no need to
> > 'assemble' internally a sparse matrix. All the other backends require
> > this. This would explain why uBLAS works.
>
> Yes I know, and I think it is weird that this problem pops up after a push 
> only touching files that handles xml files.

This is fixed now, but it's not very efficient. PeriodicBC needs to be 
looked at at some point.

Garth

> Johan