Hi, I'm trying to experiment with using external solvers. I have some questions:
1. Is there any difference in speed with calling the external software from PETSc or directly using them? 2. I tried to install MUMPS using --download-mumps. I was prompted to include --with-scalapack. After changing, I was again prompted to include --with-blacs. I changed and again I was told the need for --with-blacs-dir=<directory>. I thought I'm supposed to specify where to install blacs and entered a directory. But it seems that I need to specify the location of where blacs is. But I do not have it. So how do I solve that? 3. I installed some other external packages. I wanted to test their speed at solving equations. In the manual, I was told to use the runtime option -mat_type <mattype> -ksp_type preonly -pc_type <pctype> and also -help to get help msg. However when I tried to issue ./a.out -mat_type superlu -ksp_type preonly -pc_type lu, nothing happened. How should the command be issued? I tried to get help by running ./a.out -h what appears isn't what I want. Thank you very much. Regards. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20070212/2965ffaf/attachment.htm>