Re: [deal.II] Interpolating values of the neighbor cells in DG

On Tue, Sep 20, 2016 at 9:34 AM, Jiaqi ZHANG wrote: > Hello Praveen, > > Thank you so much. I am wondering if you could tell me which > > limiters you used, because if it is too hard for me to implement > > this limiter, I will have to try other ones. I am a newbie to C++,

Re: [deal.II] Interpolating values of the neighbor cells in DG

Hello Praveen, Thank you so much. I am wondering if you could tell me which limiters you used, because if it is too hard for me to implement this limiter, I will have to try other ones. I am a newbie to C++, but will try to read your codes to see if I can make it. Thanks, Jiaqi 2016-09-19

Re: [deal.II] Interpolating values of the neighbor cells in DG

Dear Prof. Bangerth, I will have to use arbitrary meshes, because I have solid particles moving in the mesh and have to refine the mesh adaptively. Later, I will need to move the mesh and even regenerate the mesh if the cells are too distorted. Best, Jiaqi 2016-09-19 23:26 GMT-04:00

Re: [deal.II] Interpolating values of the neighbor cells in DG

Hello Jiaqi I was interested in this some years back though I didnt pursue it after some initial attempt. See this https://groups.google.com/forum/m/?hl=en-GB#!topic/dealii/gaongNBSXfY I tried writing an fespace based on FE_DGPNonparametric which does not use a mapping and the shape functions

Re: [deal.II] Interpolating values of the neighbor cells in DG

Jiaqi, Yes, I want to extend the solution from the neighboring cells to the current cell. I know different cells have different polynomial descriptions, but in order to apply the limiters, information from the neighbor cells is required. Is it possible to extend the solutions from neighbors

Re: [deal.II] Interpolating values of the neighbor cells in DG

Dear Prof. Bangerth, Thanks for the fast reply. Yes, I want to extend the solution from the neighboring cells to the current cell. I know different cells have different polynomial descriptions, but in order to apply the limiters, information from the neighbor cells is required. Is it possible

Re: [deal.II] Interpolating values of the neighbor cells in DG

On 09/19/2016 03:15 PM, Jiaqi ZHANG wrote: I was trying to get the values of the solution polynomial in the neighbor cells in DG, for example, I want to compute View the MathML source where p_i are the solution polynomials of the neighbors, \Delta_0 is the current cell. I cannot find any

[deal.II] Interpolating values of the neighbor cells in DG

Dear all, I was trying to get the values of the solution polynomial in the neighbor cells in DG, for example, I want to compute [image: View the MathML source] where p_i are the solution polynomials of the neighbors, \Delta_0 is the current cell. I cannot find any function to do this in

Re: [deal.II] Re: Can we say that the higher order method, the more accurate?

You will also encounter the limits of our implementation of our quadrature formulas and our polynomial evaluation. Both are not stable for high order, and thus at some point approximation will stall. Best, Guido -- Prof. Dr. Guido Kanschat Interdisziplinäres Zentrum für Wissenschaftliches

[deal.II] Re: Can we say that the higher order method, the more accurate?

On Monday, September 19, 2016 at 2:12:31 AM UTC-4, Martin Kronbichler wrote: > > > In addition to what Daniel and Wolfgang said: One does definitely benefit > from going to higher degrees and deal.II is able to handle this (the > accurate boundary representation by a mapping is one thing that

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

Joel, > [...] > for (unsigned int q_index=0; q_indexfor (unsigned int i=0; i { > velocity[local_dof_indices[i]] = local_velocity_values[q_index]; > } > > Here you assign the same Tensor<1,dim> at all DoFs

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

Dear J-P, Ok, I tried to to use the FEValueExtractors but I am not sure if my code is working correctly. std::vector> velocity; velocity.resize (dof_handler_scalar.n_dofs()); QGauss quadrature_formula(dof_handler.get_fe().degree+1); FEValues

[deal.II] Re: Can we say that the higher order method, the more accurate?

Dear Jaekwank, In addition to what Daniel and Wolfgang said: One does definitely benefit from going to higher degrees and deal.II is able to handle this (the accurate boundary representation by a mapping is one thing that is easily forgotten). In a recent preprint, we considered the flow