Maybe one question would be , "why not provide SparseMatrix with a templated add_matrix method that only requires the dense matrix equivalent to support (i,j) ?" Similar signature for the vector and method shown below,
> dof_map.constrain_element_matrix_and_vector (Ke, Fe, dof_indices) Is there a performance or other issue? This would make it easier for the user to manage memory for his arrays but that could be good or bad :) Thanks. ---------------------------------------- > From: marchy...@hotmail.com > To: jwpeter...@gmail.com > Date: Mon, 22 Aug 2016 10:51:22 -0400 > CC: libmesh-users@lists.sourceforge.net > Subject: Re: [Libmesh-users] DenseSubMatrix and DenseSubVector lack of ctor > and operators > > > > > > > ________________________________ >> From: jwpeter...@gmail.com >> Date: Mon, 22 Aug 2016 08:28:18 -0600 >> Subject: Re: [Libmesh-users] DenseSubMatrix and DenseSubVector lack of >> ctor and operators >> To: marchy...@hotmail.com >> CC: libmesh-users@lists.sourceforge.net >> >> >> >> On Mon, Aug 22, 2016 at 7:53 AM, Mike Marchywka >> <marchy...@hotmail.com<mailto:marchy...@hotmail.com>> wrote: >> I was trying to move some code around related to the vars typically >> called Ke and Fe >> but encountered several errors due to missing ctor or operators such as >> assignment. >> Can someone comment on the benefit of or need for these restrictions? >> >> I think you are probably referring to a default constructor for >> DenseSubMatrix, i.e. one that does not need a reference to a parent >> matrix in order to be created? I don't think this is a good >> idea/necessary, as it would introduce extra bookkeeping and potentially >> make DenseSubMatrix too easy to use incorrectly... >> >> >> I was trying to clean up >> my own code a bit and debating about how to handle things which seem to often >> be compile time constants. One possibility is to create a code generator that >> creates specific c++ code for a given set of conditions. This is ok if >> there are some >> compiler optimizations that just not easy with other approaches. Thanks. >> >> >> >> DMN Ke; DVN Fe; >> //DSM Ke_var; DSV Fe_var; >> DSM Ke_var; // [mla.nvar][mla.nvar]; >> DSV Fe_var; // [mla.nvar] ; >> // InitMats(Ke,Fe,Ke_var,Fe_var,mla.nvar); >> >> What specifically is a compile-time constant limitation here from libmesh? >> >> >> >> //const IdxTy dofsz=dof_indices.size(); >> //const IdxTy dofsz=mla.di.dof_indices_var[0].size(); >> //Ke.resize (dofsz,dofsz); Fe.resize (dofsz); >> /* >> DSM Ke_var[mla.nvar][mla.nvar] = >> { >> { DSM(Ke), DSM(Ke), DSM(Ke), DSM(Ke)}, >> { DSM(Ke), DSM(Ke), DSM(Ke), DSM(Ke)}, >> { DSM(Ke), DSM(Ke), DSM(Ke), DSM(Ke)}, >> { DSM(Ke), DSM(Ke), DSM(Ke), DSM(Ke)} >> }; >> >> DSV Fe_var[mla.nvar] = {DSV(Fe), DSV(Fe), DSV(Fe), DSV(Fe) }; >> >> Are you just wanting to know how to create dynamically-size 2D arrays >> at runtime? > > Yes, I guess that would do it but then the question is why > the examples differ from that method. Certainly compile time > does give the compiler more opportunities to optimize. > > There is any object that can do this internally, > > Ty * Ke_var_data = new Ty[n*m] ? > > and I would have guessed that for best performance you have some way of > organizing memory. > >>From what I have now, I only need to be able to interface to these things >>from the > function that assembles the FEM RHS and LHS, > > dof_map.constrain_element_matrix_and_vector (Ke, Fe, dof_indices); > system.matrix->add_matrix (Ke, dof_indices); > system.rhs->add_vector (Fe, dof_indices); > > I could probably check the documentation but are any of there templated or > accept iterators > or do they require these libmesh DenseSub types? > > Thanks. > > >> >> -- >> John > > ------------------------------------------------------------------------------ > _______________________________________________ > Libmesh-users mailing list > Libmesh-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/libmesh-users ------------------------------------------------------------------------------ _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
