From: Yujie <recrusader@gm...>  20070830 06:45:08

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. Regards, Yujie On 8/30/07, Roy Stogner <roystgnr@...> 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. >  > Roy > 