On 6 May 2011 16:27, Tim Prince <tcpri...@live.com> wrote: > If you want to use the MPI Fortran library, don't convert your Fortran to C. > It's difficult to understand why you would consider f2c a "simplest way," > but at least it should allow you to use ordinary C MPI function calls.
Sorry, maybe I wasn't clear. Just to clarify, all of *my* code is written in C++ (because I don't actually know Fortran), but I want to use some function from PARPACK which is written in Fortran. I think I originally used f2c because it was a massive pain linking to a Fortran library. I suppose I could give it another go, but I don't think it affects the problem of mixing APIs (since the f2c version still uses the Fortran API). > The MPI Fortran library must be built against the same Fortran run-time > libraries which you use for your own Fortran code. The header files for the > Fortran MPI calls probably don't work in C. It would be a big struggle to > get them to work with f2c, since f2c doesn't have much ability to deal with > headers other than its own. Yeah I've had to manually recreate C versions of the Fortran headers (mpif.h), which is a pain and the main reason I want to try a different method. > There's no reason you can't make both C and Fortran MPI calls in the same > application. If you mean mixing a send from one language with a receive in > another, I think most would avoid that. I'm fairly sure that there wouldn't ever be a send in one language and a receive in another, but I would be doing independent sends/receives with different languages (one after another), something like this: MPI_Init(argc, argv); // C. call mpi_send(..., MPI_DOUBLE_PRECISION, ...); // Fortan. // ... MPI_AllGatherV(..., MPI_DOUBLE, ...); // C, but completely separate from previous communications. MPI_Finalize(); // C. > Whether someone uses OpenMP has little to do with choice of MPI > implementation. Some of us still may be cursing the choice of OpenMPI for > the name of an MPI implementation. Oops, that was a typo - I meant OpenMPI! I'm not actually using OpenMP at all. Thanks for the help! Tim
