Re: [deal.II] Re: PETScWrappers::MPI::Vector Vs parallel::distributed::Vector

2016-08-28 Thread Praveen C
Hello This is more of a question. There is this function PETScWrappers::VectorBase::extract_subvector_to http://www.dealii.org/developer/doxygen/deal.II/classPETScWrappers_1_1VectorBase.html#ae0f3a2b5fc8e2201237fad86ae69142e which should give faster access to the vector elements ??? >From what

Re: [deal.II] Re: where and how should I use the MeshWorker class? how should I do to implement DG without MeshWorker?

2016-08-28 Thread Wolfgang Bangerth
On 08/27/2016 08:45 PM, yoczh...@gmail.com wrote: Actually, I also want to use the MeshWorker, what worried me is that I can't control MeshWorker by myself, it something likes I know the MeshWorker can do lots of thing, but I don't know how to use MeshWorker. I am just beginning to use deal.ii

Re: [deal.II] Re: PETScWrappers::MPI::Vector Vs parallel::distributed::Vector

2016-08-28 Thread Martin Kronbichler
Dear David, Your example of accessing all elements in a vector individually by operator [] (or operator ()) is not very representative of the typical situation in most codes. All vector interfaces implement vector addition, scaling, and inner products such that you will not have to write the

[deal.II] Re: PETScWrappers::MPI::Vector Vs parallel::distributed::Vector

2016-08-28 Thread David F
Hi, thanks for your answer. I have measure the time it takes for PETScWrappers::MPI::Vector, parallel::distributed::Vector< Number > and Vector< Number > to complete a very simple task consisting of accessing the elements of these vectors. Something like this (repeating this whole process 15 ti

[deal.II] Re: PETScWrappers::MPI::Vector Vs parallel::distributed::Vector

2016-08-28 Thread David F
Hi, thanks for your answer. I have measured the time it takes for PETScWrappers::MPI::Vector, parallel::distributed::Vector< Number > and Vector< Number > to complete a very simple task, consisting in simple accessing the elements and assigning them to another variable, something like: double