The most robust way to do this, such that it doesn't depend on libMesh implementation details, is to declare a system with Ndim components stored at the nodes, and then access the rhs/solution components through their dof indices as you usually would.
If you want to manually compute the average rather than form a linear system you can simply create an ExplicitSystem. -Ben On Mar 11, 2013, at 9:52 PM, "Subramanya Gautam Sadasiva" <[email protected]> wrote: > I am trying to create a method to average gradient values at the quadrature > points to the nodes. > To do this, I create a FEVector System, and you essentially have something > like > [N^T N][gradient_at_nodes] = [gradient_at_qp] > While constructing the gradient_at_qp vector i am unable to figure out how to > add them to the element rhs. > For the default version, if n_dofs is the number of nodes, my loop should be > doing > for (i=0; i<n_dofs; i++) > { > for (j=0; j<_dim; j++) > Fe(n_dofs*i+j) = terms(j) > } > > Does the above sound okay? > > Thanks, > > > > Subramanya Sadasiva > > "But memory eventually fades. Turbulences damp out, internal strains yield to > plastic flow, concentration inhomogeneities diffuse to uniformity. Systems > tend to subside to very simple states,independent of their specific history." > Herbert Callen . Thermodynamics and an Introduction to Thermostatics. > > ----- Original Message ----- > From: "John Peterson" <[email protected]> > To: "Subramanya Gautam Sadasiva" <[email protected]> > Cc: "libmesh-users" <[email protected]> > Sent: Monday, March 11, 2013 11:35:04 PM > Subject: Re: [Libmesh-users] FEVectorBase element base. > > > > > > > > On Mon, Mar 11, 2013 at 9:30 PM, Subramanya Gautam Sadasiva < > [email protected] > wrote: > > > Hi, > How are the components arranged in the solution vector for each element? are > the degrees of freedom arranged as (for a linear quadrilateral element) > [1 1 1 1 2 2 2 2 3 3 3 3] or is it [1 2 3 1 2 3 1 2 3 1 2 3]. I am unable to > figure out the code in fe.C . > > > > I think by the first you mean "var major" ordering (?) which is the default > in libmesh. The second can be enabled by passing -- node - major -dofs on the > command line. > > > -- > John > > ------------------------------------------------------------------------------ > Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester > Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the > endpoint security space. For insight on selecting the right partner to > tackle endpoint security challenges, access the full report. > http://p.sf.net/sfu/symantec-dev2dev > _______________________________________________ > Libmesh-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/libmesh-users ------------------------------------------------------------------------------ Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the endpoint security space. For insight on selecting the right partner to tackle endpoint security challenges, access the full report. http://p.sf.net/sfu/symantec-dev2dev _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
