[Getfem-users] Example of a simple mixed-problem, or problem with two variables

[Jehanzeb Hameed]

Hello,

Is there a simple example in getfem where assembly is for two
variables? E.g. we may want to solve for "u" and "q" (with an equation
defining the relationship between u and q) . Such a case arises in
mixed methods.  Is there an example for mixed-poisson problem
somewhere? I know mixed-elasticity problem is given with getfem, but I
am not familiar with that particular problem.

In particular, I am not sure how to refer to "q" and "u" in
generic_assembly routines. Say my weak form involves div(q) . v ? How
will I write this in "assem.set" routine? (I am guessing thats what I
am supposed to do).

Thanks,
-Jehanzeb