Broadcasts share data of arbitrary length, assuming all participants know the source.
This call allows subgrids to be aligned to the original grid in reasonably general ways, but requires a basic cartesian subgridding, in that each subgrid defined must be a rectangular collection of processes. Finally, it is often necessary to determine the grid shape , as well as the current process's location on the grid , when using two-dimensional logical grids. The following calls provide simple access to these four quantities.