On Jun 27, 2013, at 2:23 PM, Tabrez Ali <[email protected]> wrote:
> Fortran can be tricky. > > Try to run the program in valgrind and/or recheck all your arguments. I once > forgot MatAssemblyType in the call to MatAssembly and the code still ran fine > on one machine but failed on other. It is better to test with at least 2-3 > compilers (GNU, Solaris and Open64 Fortran/C compilers are all free on Linux). > > T You can also run both versions with -snes_monitor -ksp_monitor and see if they both start out the same way. Barry > > > On 27.06.2013 14:52, Longxiang Chen wrote: >> Dear all, >> >> I use ksp_solver to solve Ax=b, where A is from an outer loop of PDE. >> Under debug mode(default), it solves the problem in about 4000 >> iterations. >> And the final answer is correct (comparing to another solver). >> >> I use intel compiler. >> The program is in Fortran (by mpif90), except the solver is in c (by >> mpicc). >> >> However, when I re-configure with --with-debugging=0 (the only >> change), >> the program terminates in about 30 iterations with the wrong final >> solution. >> >> Thank you. >> >> Best regards, >> Longxiang Chen >> >> Do something everyday that gets you closer to being done. >
