Re: [deal.II] computing some other output quantity after solution is calculated.

2016-10-31 Thread hanks0227
Dr, Bangerth, > >u_h(x) = \sum_i U_i \varphi_i(x) > > First of all, I'm really sorry to bother you continuously... Could I have please one more question? I also wanted to calculate l2 norm of |u_h(x)-u_h_exact(x)| (where u_h_exact(x) is exact solution of u_h(x)). So what I did is fo

Re: [deal.II] computing some other output quantity after solution is calculated.

2016-10-31 Thread Wolfgang Bangerth
On 10/31/2016 08:11 PM, hanks0...@gmail.com wrote: But, my question was that in usual tutorial program of deal.II, the vector solution contains values for U_i not u_h(x). We use them interchangeably. The *solution vector* that comes out of the linear solver is U_i, and it corresponds to the *

Re: [deal.II] computing some other output quantity after solution is calculated.

2016-10-31 Thread hanks0227
> > > Well, both are the solution -- one is a function of x, the other is a > vector > of nodal values, but they ultimately represent the same object. U_i is the > vector you get out of the linear solver. > I'm sorry to make you confused I should have been more specific. But, my question was

Re: [deal.II] mesh generation for arbitrary boundary

2016-10-31 Thread hanks0227
Dr. Bangerth, I'm sorry... I found the similar question about this problem. That's why I eliminate my question... Anyway Thank you very much for your reply. Kyusik. 2016년 11월 1일 화요일 오전 2시 22분 58초 UTC+9, Wolfgang Bangerth 님의 말: > > On 10/31/2016 04:00 AM, hank...@gmail.com wrote: > > > > I

Re: [deal.II] computing some other output quantity after solution is calculated.

2016-10-31 Thread Wolfgang Bangerth
This is one way to do it. You are just projecting J_tor to a finite element space and use that for output or further processing. As others have already noted, the only problem I can see is that computing solution_max may be inaccurate. This is because in general, if you have

Re: [deal.II] computing some other output quantity after solution is calculated.

2016-10-31 Thread hanks0227
Dr. Bangerth, Thank you very much for your kind reply. > This is one way to do it. You are just projecting J_tor to a finite > element space and use that for output or further processing. As others > have already noted, the only problem I can see is that computing > solution_max may be inacc

Re: [deal.II] Re: Convergence problem arising for large number of DoFs

2016-10-31 Thread Bruno Turcksin
Hamed, 2016-10-31 15:56 GMT-04:00 Hamed Babaei : > I have already checked SSOR and AMG non of them make a difference . ILU > doesn't work and gives this error: "[0]PETSC ERROR: MatSolverPackage petsc > does not support matrix type mpiaij" What do you mean they don't make a difference? You should g

[deal.II] Re: Convergence problem arising for large number of DoFs

2016-10-31 Thread Hamed Babaei
Dear Bruno, I have already checked SSOR and AMG non of them make a difference . ILU doesn't work and gives this error: "[0]PETSC ERROR: MatSolverPackage petsc does not support matrix type mpiaij" I don't know how to increase number of iteration. Although I have used the "SolverControl solver_c

[deal.II] Re: Convergence problem arising for large number of DoFs

2016-10-31 Thread Bruno Turcksin
Hamed, On Monday, October 31, 2016 at 3:01:20 PM UTC-4, Hamed Babaei wrote: > > This error message can indicate that you have simply not allowed a > sufficiently large number of iterations for your iterative solver to > converge. This often happens when you increase the size of your problem. In

[deal.II] Convergence problem arising for large number of DoFs

2016-10-31 Thread Hamed Babaei
Hi all, I have parallelized a code in which I use GMRES or Bicgstab solvers with BlockJacobi preconditioner for a symmetric but not possitive-difinite system matrix. The problem is that it converges for 15 DoFs and fewer (on 1 node with 16 processor) but does'nt converge for larger number o

Re: [deal.II] mesh generation for arbitrary boundary

2016-10-31 Thread Wolfgang Bangerth
On 10/31/2016 04:00 AM, hanks0...@gmail.com wrote: I made the c++ code(make_grid2D_ver2.cc) that creates UCD format(B_coord2D_ver2.inp) for arbitrary shape boundary(boundary.dat) But it turns out that this one is not good mesh.(I attached the picture for the mesh grid.png) So, I am looking for

Re: [deal.II] computing some other output quantity after solution is calculated.

2016-10-31 Thread Wolfgang Bangerth
Kyusik, I'm trying to calculate J_tor= x*solution+solution_max/y solution is already calculated vector from 3 function (setup_system, assemble_system, solve) To do this calculation I added the following three function(setup_Jtor, assmeble_Jtor, solve_Jtor) [...] This is one way to do it. Y

[deal.II] Re: computing some other output quantity after solution is calculated.

2016-10-31 Thread hanks0227
Daniel, > If you know that your FiniteElement is interpolating (which I assume given > the way you compute the maximum) and that J_tor= x*solution+solution_max/y > is in your ansatz space (probably not) or an interpolation is sufficient, > you can use something like > > J_tor(local_dof_indices

[deal.II] Re: computing some other output quantity after solution is calculated.

2016-10-31 Thread Daniel Arndt
Kyusik, > I defined Function for right_hand_side. > > template > double RightHandSide::value (const Point &p, > const double psi, > const double psi_max, > const unsigned int /*component*/) const > { > double rhs; > rhs = p(0)*psi+psi_max/p(1); >

[deal.II] Re: computing some other output quantity after solution is calculated.

2016-10-31 Thread hanks0227
> First of all, Thank you very much for your reply > > This can only work if you know that the maximum is attained at one of the > support_points > of your FiniteElement. In general, you can use > VectorTools::integrate_difference to find a good approximation > to the maximum value of your

[deal.II] Re: computing some other output quantity after solution is calculated.

2016-10-31 Thread Daniel Arndt
Kyusik, //by Han(To get psi0) > Vector::iterator max; > max=std::max_element(solution.begin(),solution.end()); > This can only work if you know that the maximum is attained at one of the support_points of your FiniteElement. In general, you can use VectorTools::integrate_difference to find

[deal.II] computing some other output quantity after solution is calculated.

2016-10-31 Thread hanks0227
Hi All, I'm trying to calculate J_tor= x*solution+solution_max/y solution is already calculated vector from 3 function (setup_system, assemble_system, solve) To do this calculation I added the following three function(setup_Jtor, assmeble_Jtor, solve_Jtor) template void Step6::setup_Jtor

[deal.II] Re: what do SolverControl do for Direct Solvers?

2016-10-31 Thread 'Uwe Köcher' via deal . II User Group
Dear Hamed, when we installed dealii and its dependencies on the cluster, I think we > didn't uncomment the "#PACKAGES="${PACKAGES} once:superlu_dist" in > candi.cfg so it seems we need to install them again. > indeed, but make sure that parmetis is enabled also. > I want to solve my proble