On Wed, Apr 2, 2014 at 8:23 AM, Xiangdong <[email protected]> wrote:
> Hello everyone, > > I have two quick questions about src/snes/examples/tutorials/ex3.c. > > 1) In line 150-151, why do we need to call MatSeqAIJSetPreallocation > before MatMPIAIJSetPreallocation? I found that without the seqaij call, the > program crashed. However, the mat J we want to create is the mpiaij. > One is used in serial, the other in parallel. Really, you can just call http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatXAIJSetPreallocation.html Matt > 2) In line 390-397, it sets the values of the residue function at the > boundary. Where do these values come from? In other words, I am not clear > about ff[0]=xx[0] and ff[xs+xm-1] = xx[xs+xm-1] - 1.0; > > Thank you. > > Xiangdong > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
