Re: [deal.II] Re: FE w/ Gauss Point DoFs

On 03/07/2018 08:43 AM, Jonathan Russ wrote: Thank you for your fast reply. I'm sorry I'm not doing a great job of explaining this. Here is an example from elasticity that illustrates what I would like: In this case there are displacement degrees of freedom at the nodes but the stress is a qu

Re: [deal.II] Shape function derivative wrt to a different cell

On 03/07/2018 12:19 PM, RAJAT ARORA wrote: I want to do the following thing: I have a scalar quantity available only at the Gauss points of a cell. (cell = 2d rectangular element) I want to get the derivative of this quantity at the center of the cell. One way to do this is to locally project t

[deal.II] Useless and biased performance check

Hi all, I discussed the preconditioned CG method today in class (with SSOR and optimal relaxation parameter applied to the beloved Laplace problem.) I was quite surprised that I was able to solve the problem for 1 million degrees of freedom in about 9 seconds and 80 CG iterations with Julia (that

[deal.II] Re: How to call project_matrix_free?

Hi Maxi, To build on what Daniel said in the other thread: This function was written with the intent that users would just call `project`. `project_matrix_free` is not really part of the public interface (though perhaps we should change this). You will need to `#include ` to get the `project

[deal.II] Shape function derivative wrt to a different cell

Hello all, I am using deal.ii to solve a 2d solid mechanics problem. I want to do the following thing: I have a scalar quantity available only at the Gauss points of a cell. (cell = 2d rectangular element) I want to get the derivative of this quantity at the center of the cell. One way to do thi

Re: [deal.II] FE w/ Gauss Point DoFs

Thank you Jean-Paul! That seems to be precisely what I should use assuming the number of degrees of freedom per cell is equal to the number of quadrature points per cell (which it appears to be). Thanks again! Jonathan On Wednesday, March 7, 2018 at 12:54:06 PM UTC-5, Jean-Paul Pelteret wrote: >

Re: [deal.II] FE w/ Gauss Point DoFs

Dear Jonathan, Is FE_DGQArbitraryNodes perhaps what you’re looking for? From the documentation: > The primary purpose of this class is to provide an element for which the mass > matrix can be made diagonal by choosing ba

Re: [deal.II] Re: FE w/ Gauss Point DoFs

Bruno - Thank you for your help. I see what you are saying. In this way I would need to make sure I have the same number of gauss points as nodes in the finite element since deal.II will assume that the stress degrees of freedom are associated with the nodes. For now I don't believe this is too

Re: [deal.II] Re: FE w/ Gauss Point DoFs

Jonathan, 2018-03-07 10:43 GMT-05:00 Jonathan Russ : > > Thank you for your fast reply. I'm sorry I'm not doing a great job of > explaining this. Here is an example from elasticity that illustrates what I > would like: > In this case there are displacement degrees of freedom at the nodes but > th

[deal.II] Re: FE w/ Gauss Point DoFs

I'm hesitating to refer to this as an element with internal nodes. The displacement degrees of freedom would still be interpolated with bilinear shape functions but the gauss point degrees of freedom are not interpolated over the element. They are independent of the other gauss point degrees of

[deal.II] Re: FE w/ Gauss Point DoFs

Some people refer to this as an element with internal nodes. On Wednesday, March 7, 2018 at 10:43:13 AM UTC-5, Jonathan Russ wrote: > > Hi Bruno - > > Thank you for your fast reply. I'm sorry I'm not doing a great job of > explaining this. Here is an example from elasticity that illustrates what

[deal.II] Re: FE w/ Gauss Point DoFs

Hi Bruno - Thank you for your fast reply. I'm sorry I'm not doing a great job of explaining this. Here is an example from elasticity that illustrates what I would like: In this case there are displacement degrees of freedom at the nodes but the stress is a quantity typically derived from the di

[deal.II] Re: FE w/ Gauss Point DoFs

Jonathan, On Wednesday, March 7, 2018 at 10:20:44 AM UTC-5, Jonathan Russ wrote: > > Is there a FiniteElement in deal.II that allows the addition of degrees of > freedom at gauss points so that the DoFHandler object also manages them? > For example, I would like to have just a standard Lagrangia

[deal.II] FE w/ Gauss Point DoFs

Hello - I apologize since this question is likely obvious to most, but a quick search didn't reveal the answer to me. Is there a FiniteElement in deal.II that allows the addition of degrees of freedom at gauss points so that the DoFHandler object also manages them? For example, I would like t

Re: [deal.II] Setting ConditionalOStream in a function

On 03/07/2018 01:48 AM, 'Maxi Miller' via deal.II User Group wrote: Usually the ConditionalOStream-variable is initialized in the constructor of the object, as for example in | template MinimalSurfaceProblem::MinimalSurfaceProblem(constchar*file_name) : mpi_communicator(MPI_COMM_WORLD),

Re: [deal.II] Experimental data at output boundary

On 03/07/2018 12:45 AM, 'Joaquin' via deal.II User Group wrote: I am trying to insert experimental data from a file at the output boundary of a tube. Is it possible to do that in deal.II? I attach the file of experimental data, pressure vs time. You can of course read data from a file into m

[deal.II] How to call project_matrix_free?

Based on my question here: https://groups.google.com/d/msg/dealii/4YoJZ8d2-XM/0k3TjZrqAAAJ I would like to implement the suggested solution using project_matrix_free() and project_matrix_free_vector(). I thus try to call them as VectorTools::project_matrix_free(MappingQGeneric(1),

Re: [deal.II] Re: Iterating over all the entries in a PETScWrapper::MPI::SparseMatrix in parallel

This time I used VectorOperation::insert and it didn't happen the memory error that I posted before. OK, so that then clearly helps :-) However, if I put the compress function after the loop, it only sets one entry on each rank then throws the exception "Object is in wrong state, not for

[deal.II] Setting ConditionalOStream in a function

Usually the ConditionalOStream-variable is initialized in the constructor of the object, as for example in template MinimalSurfaceProblem::MinimalSurfaceProblem (const char *file_name) : mpi_communicator(MPI_COMM_WORLD), triangulation(mpi_communicator, typename