dolfin team mailing list archive

[Johan Jansson <jjan@xxxxxxxxxx>]

Garth N. Wells wrote:
> Johan Jansson wrote:
> > Anders Logg wrote:
> > > On Mon, Dec 03, 2007 at 01:05:51AM +0100, DOLFIN wrote:
> > >
> > >  
> > > > changeset:   3430:4fa0790a4fc34d3abac3079644368813a252ac61
> > > > parent:      3428:7967082310c3ab03df9d812a6f471dcf988e7b4e
> > > > user:        "Johan Jansson <jjan@xxxxxxxxxx>"
> > > > date:        Sun Dec 02 20:17:50 2007 +0100
> > > > files:       src/kernel/ode/MonoAdaptiveJacobian.cpp 
> > > > src/kernel/ode/MonoAdaptiveNewtonSolver.cpp src/kernel/ode/ODE.cpp 
> > > > src/kernel/ode/TimeSlabJacobian.cpp 
> > > > src/kernel/ode/dolfin/MonoAdaptiveJacobian.h 
> > > > src/kernel/ode/dolfin/MonoAdaptiveNewtonSolver.h 
> > > > src/kernel/ode/dolfin/ODE.h 
> > > > src/kernel/ode/dolfin/TimeSlabJacobian.h 
> > > > src/kernel/parameter/dolfin/DefaultParameters.h
> > > > description:
> > > > ODE:
> > > >
> > > > Added support for computing the Jacobian as a sparse matrix (only for
> > > > mono-adaptive dG(0) and cG(1) so far, and only for PETSc).
> > > >     
> > > Why PETSc? The ODE solvers are tied to uBlas so the vectors won't be
> > > parallel.
> > >
> > > How and when should this be used? Does it change anything in the
> > > computation that the ODE solver does, or is it just a utility function
> > > for computing the Jacobian that a user can call?
> > >   
> > Ideally the ODE solver should support both uBlas and PETSc, I think 
> > the plan should be to transition to a general implementation if we 
> > start to use it more for PDE. PETSc has a higher priority than uBlas 
> > though, since that's what we use for large computations (due to 
> > efficiency and robustness), and since it's parallel while uBlas is not.
>
> Why don't you try to implement it through the common interface?  We'll 
> soon have more linear algebra back-ends (e.g. Trilinos).
>
> Garth
Yes, rewriting the ODE solver with the general linear algebra interface 
is on my todo-list. If the ODE interface is used more, then the 
incentive to do this will increase more (since otherwise we cannot use 
it in parallel for instance).

However, right now updating and releasing the things we already have 
working has top priority.

 Johan