[petsc-users] I write the following program, it can converge with 4 processor, but can not converge with 2 , or 3 processor. Could you help me out

/* Program usage: mpiexec ex1 [-help] [all PETSc options] */ static char help[] = Basic vector routines.\n\n; #include petscksp.h #include petscvec.h int main(int argc,char **argv) { int N=16; int MyRank; Mat A; PC Pc; KSP ksp; Vec b,x;

Re: [petsc-users] I write the following program, it can converge with 4 processor, but can not converge with 2 , or 3 processor. Could you help me out

On Fri, Aug 16, 2013 at 6:13 AM, 丁老师 ztdepya...@163.com wrote: Its common for iterative solvers to converge differently for different PC. You are using block Jacobi-ILU which is different for different numbers of processes. Matt /* Program usage: mpiexec ex1 [-help] [all PETSc options] */

Re: [petsc-users] I write the following program, it can converge with 4 processor, but can not converge with 2 , or 3 processor. Could you help me out

thank you very much! could you please suggest me a robust preconditioner which is independent of the number of processor. 在 2013-08-16 19:54:01，Matthew Knepley knep...@gmail.com 写道： On Fri, Aug 16, 2013 at 6:13 AM, 丁老师 ztdepya...@163.com wrote: Its common for iterative solvers to

Re: [petsc-users] I write the following program, it can converge with 4 processor, but can not converge with 2 , or 3 processor. Could you help me out

On Fri, Aug 16, 2013 at 7:32 AM, 丁老师 ztdepya...@163.com wrote: thank you very much! could you please suggest me a robust preconditioner which is independent of the number of processor. For generic problems, they do not exist. I suggest looking in the literature for your specific problem, and