Partition definition

The coupling fields sent or received by a component are usually scattered among the different component processes. With OASIS3-MCT, all processes exchanging coupling data have to express in a global index space the local partitioning of the different grids onto which the data is expressed (see [*] for the grid definition). The processes not implied in the coupling do not have to call this routine (for backward compatibility with OASIS3-MCT_2.0, they may still call it describing a null partition, i.e. with ig_paral(:)=0).