Re: [deal.II] Unexpected behavior when using GridGenerator::subdivided_hyper_rectangle in parallel

2020-07-30 Thread Jimmy Ho
Hi Dr. Bangerth, Thanks a lot for the clarification! They are really helpful! Best, Jimmy On Thursday, July 30, 2020 at 11:47:21 AM UTC-5, Wolfgang Bangerth wrote: > > On 7/30/20 10:11 AM, Jimmy Ho wrote: > > > > As a follow-up question, upon calling compress(), will the local copy of > the

Re: [deal.II] Unexpected behavior when using GridGenerator::subdivided_hyper_rectangle in parallel

2020-07-30 Thread Wolfgang Bangerth
On 7/30/20 10:11 AM, Jimmy Ho wrote: As a follow-up question, upon calling compress(), will the local copy of the system matrix on a specific processor get updated to contain information from all other processors? In other words, if I print out the system matrix from a particular processor

Re: [deal.II] Unexpected behavior when using GridGenerator::subdivided_hyper_rectangle in parallel

2020-07-30 Thread Jimmy Ho
Hi Dr. Bangerth, As a follow-up question, upon calling compress(), will the local copy of the system matrix on a specific processor get updated to contain information from all other processors? In other words, if I print out the system matrix from a particular processor after calling

Re: [deal.II] Unexpected behavior when using GridGenerator::subdivided_hyper_rectangle in parallel

2020-07-30 Thread Jimmy Ho
Hi Dr. Bangerth, Thanks a lot for your guidance! I compared the solution in the vtu files using the minimal example above, they are nearly identical. Looking back into the code, I am outputting the system matrix from processor 0, which probably only printed the part that it locally owns, hence

Re: [deal.II] Unexpected behavior when using GridGenerator::subdivided_hyper_rectangle in parallel

2020-07-29 Thread Wolfgang Bangerth
Jimmy, A minimum example to reproduce this is attached. When the mesh is built using GridGenerator::hyper_cube or GridGenerator::subdivided_hyper_rectangle with subsequent refinement, the program works as expected. When the same mesh is generated using

[deal.II] Unexpected behavior when using GridGenerator::subdivided_hyper_rectangle in parallel

2020-07-28 Thread Jimmy Ho
Hi All, I am using the Step 40 tutorial to build a parallel program using MPI. The code runs but generates different results when using one and multiple processors. After stripping it down to the bare minimum, it appears that when the mesh is built using