Re: [deal.II] Neumann bc in step-20

Ok, thanks Wolfgang and Daniel! I will follow your advise and post updates on this issue. /Erik 2016-09-30 5:54 GMT+02:00 Wolfgang Bangerth : > On 09/28/2016 11:32 PM, Erik Svensson wrote: > >> >> >> I’m trying to implement homogeneous Neumann bc on part of the boundary in >> tutorial example s

Re: [deal.II] Re: a few questions about matrix-free

Hi Steve, Thank for your reply. > On 30 Sep 2016, at 02:15, Stephen DeWitt wrote: > > Hi Denis, > I'm sure there is someone more knowledgable than me, but I'll take a crack at > a couple of these: > > (2/3) Maybe I'm misunderstanding your circumstances, but if all you need is > different upd

Re: [deal.II] Neumann bc in step-20

On 09/28/2016 11:32 PM, Erik Svensson wrote: I’m trying to implement homogeneous Neumann bc on part of the boundary in tutorial example step-20. The Neumann bc should be imposed strongly (as for Dirichlet bc in normal, non-mixed, formulation). Is this correct? In any case, I’m trying to impos

[deal.II] Re: a few questions about matrix-free

Hi Denis, I'm sure there is someone more knowledgable than me, but I'll take a crack at a couple of these: (2/3) Maybe I'm misunderstanding your circumstances, but if all you need is different update flags for different fields you can do that with a single MatrixFree object, but set different f

[deal.II] Re: Trilinos SparseMatrix mmult bug

So this turned out to be a bug in my own code after I made the original change in trilinos_sparse_matrix.cc. When I was constructing the sparsity patterns for the matrices using DoFTools::make_sparsity_pattern, there is a flag I had set keep_constrained_dofs = false. Setting this flag to true ha

[deal.II] Running step-17 on cluster in parallel

Dear all, I want to run step-17 on cluster. It works well with single node, but gives error when I use multiple nodes. I cannot figure out where the problem is. I believe the code is correct. It seems that the cluster cannot operate the code " GridTools::partition_triangulation (n_mpi_processe

Re: [deal.II] Relation between Solution Error Behavior and Polynomial Approximation Degree

Yes! your explanation clear explains the situation ! Thank you!!! Jaekwang Kim 2016년 9월 29일 목요일 오전 11시 25분 28초 UTC-5, Wolfgang Bangerth 님의 말: > > On 09/29/2016 09:41 AM, JAEKWANG KIM wrote: > > > > I thought that the order of error is O(h^p) where h is a mesh-size and p > > is polynomial deg

Re: [deal.II] Relation between Solution Error Behavior and Polynomial Approximation Degree

On 09/29/2016 09:41 AM, JAEKWANG KIM wrote: I thought that the order of error is O(h^p) where h is a mesh-size and p is polynomial degree we use in approximation. So, I thought that if I plot an error with number of mesh in log-log scale, than the graph will show -p slope. However, I the error

Re: [deal.II] Derivatives (gradients) of Symmetric Tensors

Metin, I need help to figure out some functions in fe_values.h and fe_values.cc sources. Could you please help me understand what's happening in the divergence function (SymmetricTensor<2, dim, spacedim>::divergence) and the symmetric_gradient function for the vectors (Vector::symmetric_gradie

[deal.II] Relation between Solution Error Behavior and Polynomial Approximation Degree

Hi all, I have question on error behavior of FEM. I thought that the order of error is O(h^p) where h is a mesh-size and p is polynomial degree we use in appr

[deal.II] Re: Vector-valued gradient of solution vector

Joel, Yes, this looks about right. I would really replace "std::vector double x,y,z" by "Vector x,y,z". In the end, entries in these vectors only make sense with the corresponding DoFHandler. This would also allow you to use these Vectors for postprocessing in deal.II. Best, Daniel -- The de

Re: [deal.II] Derivatives (gradients) of Symmetric Tensors

Dear Wolfgang, I would like to implement the gradients (or symmetric_gradient) and laplacians functions for the symmetric_tensor class. I need help to figure out some functions in fe_values.h and fe_values.cc sources. Could you please help me understand what's happening in the divergence func

[deal.II] HR event for developers seeking new projects in Berlin

Hi everyone! we are launching our first event Talents@Unicorn.Berlin and we are currently looking for developers who are seeking jobs in the IT industry in Berlin. You can register and attend for free our event on the 1st of November and meet with selected top companies (Babbel

[deal.II] Re: Vector-valued gradient of solution vector

Dear Daniel, Ok, I think I got it to work now, can you verify that it is correct or if I have missed something crucial. std::vector x,y,z; x.resize (dof_handler_scalar.n_dofs()); y.resize (dof_handler_scalar.n_dofs()); z.resize (dof_handler_scalar.n_dofs()); Quadrature quadrature

[deal.II] a few questions about matrix-free

Dear all, I have accumulated a few matrix-free related questions which i would like to clarify ask. (1) FEEvaluation has read_dof_values (const std::vector< VectorType > &src, const unsigned int first_index=0), but i don’t see a function to get to values of each DoF vector at quadrature points

[deal.II] Re: Neumann bc in step-20

Erik, Am Donnerstag, 29. September 2016 07:32:04 UTC+2 schrieb Erik Svensson: > > Hi, > > I’m trying to implement homogeneous Neumann bc on part of the boundary in > tutorial example step-20. > > The Neumann bc should be imposed strongly (as for Dirichlet bc in normal, > non-mixed, formulation

[deal.II] Re: macOS Sierra dynamic linker limit

after digging more i found out that it has to do with extra not needed LC_RPATH load commands added by Spack https://github.com/LLNL/spack/issues/1874 On Wednesday, September 28, 2016 at 5:58:07 PM UTC+2, Denis Davydov wrote: > > I am hitting run-time error of the form: > > 36: dyld: Library not