3 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 describe, in a global index space, the local partitioning of the different grids onto which the data is expressed (see 2.2.4 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). Note that with releases earlier than OASIS3-MCT_5.2 (2022/11/02), it was not allowed to associate more than one grid to one partition (this could cause problems with the global CONSERV operation).

• CALL oasis_def_partition (il_part_id, ig_paral, kinfo, ig_size, name) or
• CALL prism_def_partition_proto (il_part_id, ig_paral, kinfo, ig_size, name)
  • il_part_id [INTEGER; OUT]: partition ID
  • ig_paral [INTEGER, DIMENSION(:), IN]: vector of integers describing the local grid partition in the global index space; has a different expression depending on the type of the partition; in OASIS3-MCT, 5 types of partition are supported: Serial (no partition), Apple, Box, Orange, and Points (see below).
  • kinfo [INTEGER; OUT]: returned error code.
  • ig_size [INTEGER, OPTIONAL, IN]: Optional argument, mandatory if the coupling data is exchanged for only a subdomain of the global grid; in this case, ig_size must give the total number of grid points.
  • name [CHARACTER, OPTIONAL, IN]: Optional argument associating a name to the partition, mandatory if oasis_def_partition is called either for a grid decomposed not across all the processes of a component or if the related oasis_def_partition are not called in the same order on the different component processes; this argument is new since OASIS3-MCT_3.0 release and is linked to the greater flexibility in the configuration of components supported (see 2.1); it has a maximum length of 120 characters.