You need to cut and paste and send the entire error message: "not working" makes it very difficult for us to know what has gone wrong. Based on the code fragment you sent I guess one of your problems is that the viewer communicator is not the same as the matrix communicator. Since the matrix is on 16 processors (I am guessing PETSC_COMM_WORLD) the viewer communicator must also be the same (also PETSC_COMM_WORLD). The simplest code you can do is
PetscViewerASCIIOpen(PETSC_COMM_WORLD,"stdout",&viewer); MatView(impOP,viewer);
but you can get a similar effect with the command line option -mat_view and not write any code at all (the less code you have to write the better). Barry
On Jun 19, 2015, at 10:42 PM, Longyin Cui <[email protected]> wrote:
Hi dear whoever reads this:
I have a quick question: After matrix assembly, suppouse I have matrix A. Assuming I used 16 processors, if I want each processor to print out their local contents of the A, how do I proceed? (I simply want to know how the matrix is stored from generating to communicating to solving, so I get to display all the time to get better undersdtanding)
I read the examples, and I tried things like below and sooooo many different codes from examples, it still is not working. PetscViewer viewer; PetscMPIInt my_rank; MPI_Comm_rank(PETSC_COMM_WORLD,&my_rank); PetscPrintf(MPI_COMM_SELF,"[%d] rank\n",my_rank); PetscViewerASCIIOpen(MPI_COMM_SELF,NULL,&viewer); PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO); MatView(impOP,viewer);
Plea......se give me some hints
Thank you so very much!
Longyin Cui (or you know me as Eric); Student from C.S. division; Cell: 7407047169; return 0;