Regular Grid Example: Conclusion
Sending data
- Can use any MPI send and receive routine
- Neighbors at boundary have rank MPI_PROCNULL
- Send/receive to MPI_PROCNULL has no effect
- No explicit support for managing "ghost points"
MPI_CART_SHIFT( comm2d, 0, 1, &nbrleft, &nbrright );
MPI_CART_SHIFT( comm2d, 1, 1, &nbrbottom, &nbrtop );