Dear Renard, I cant seem to find the function "gf_asm" to use in C++ code. I see it in a .cc file in the source code for getfem, but there seems to be no prototype for it in a header file.
Do you mean that I should use getfem::generic_assembly in the way you have described? Thanks, -Jehanzeb On Sun, Jul 5, 2009 at 3:39 PM, Renard Yves<[email protected]> wrote: > > > Dear Jehanzeb, > > You have to use a volumic assembly . An example for the matrix of the > Laplace operator is > > gf_asm('volumic',['a=data(#2); ',... > 'M(#1,#1)+=sym(comp(Grad(#1).Grad(#1).Base(#2))(:,i,:,i,j).a(j))'], > mim, mf, mf_data, A); > > A matrix for a mixed term can be obtained in a same way with two mf : > > gf_asm('volumic', 'M(#1,#1)+=comp(Grad(#1).Base(#2))(:,i,i,:)', mim, mf1, > mf2); > > where mf1 should be a vectorial fem (for more details see the Getfem++ > documentation). > > Yves. > > > Jehanzeb Hameed <[email protected]> a écrit : > >> I had a look at the Stokes example. It uses model bricks to form the >> system. From the documentation, it seems using model bricks implicitly >> chooses the bilinear variational form. I would like to define my own >> bilinear form to form the matrix, in which I can define terms like >> div(q) + c u (q = vector, c = constant, u = another variable besides >> q). How would I go about this? >> >> Thanks, >> -Jehanzeb >> >> On Sun, Jul 5, 2009 at 11:05 AM, Iago Barbeiro<[email protected]> >> wrote: >>> >>> Dear Jehanzeb, >>> >>> I think you may start by looking the Stokes example. >>> It deals with two variables (û=uî+v^j and p) and has the term div(û).dp. >>> Bon courage! >>> >>> Iago >>> >>> On Sun, Jul 5, 2009 at 6:07 AM, Jehanzeb Hameed <[email protected]> >>> wrote: >>>> >>>> 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 >>>> >>>> _______________________________________________ >>>> Getfem-users mailing list >>>> [email protected] >>>> https://mail.gna.org/listinfo/getfem-users >>> >>> >> >> _______________________________________________ >> Getfem-users mailing list >> [email protected] >> https://mail.gna.org/listinfo/getfem-users >> > > > > _______________________________________________ Getfem-users mailing list [email protected] https://mail.gna.org/listinfo/getfem-users
