Dear Roy:

In the system with multiple matrixes and multiple variables, in view of adaptive mesh refinment, how to make several variables guide adaptive mesh refinement?
in view of parallel computation, what is the distribution of the matrixes in computer cluster when the user solves its problem?
Whether does the user need to add some codes for dealling with the above problems? How can the user check the corresponding information?

Thanks a lot.


On 8/30/07, Roy Stogner <> wrote:
On Wed, 29 Aug 2007, Yujie wrote:

> I want to know whether I may generate multiple system matrixes and obtain
> multiple solutions?

Yes.  Each subclass of System has its own solution vector; each
subclass of ImplicitSystem has its own matrix.  If you want to add
additional matrices the same system, use System::add_matrix() as in
example 7.  If you want to solve for different variables with
independent matrices, use EquationSystems::add_system() to add
multiple systems.

> In addition, if the problem to be solved includes several PDEs (they
> are coupled), whether is libmesh avalible? If it ok, how to deal
> with them?

Yes.  If you want the coupling to be strong, you add additional
variables to the same System object; if you want the coupling to be
weak you add additional systems to the same EquationSystems object.

For example if you're solving an incompressible flow and transport
problem, you might have one system with velocity components u,v,w and
pressure p, and a second system with concentration c.