Dear all,

I am new in OpenMPI and writing a parallel processing program using openmpi in C++ language. I would like to use the function MPI_Allreduce() but my sendbuf and recvbuf datatype are pointers/arrays (2D). 

Is it possible to pass in and out the pointers/arrays using the MPI_Allreduce() ?

If yes, hope can have some guidelines provided on how to write the command.

Thanks in advance.

Best Regards,
Shi Wei