wiki:PDAF_set_comm_pdaf

Version 1 (modified by lnerger, 10 months ago) (diff)

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PDAF_set_comm_pdaf

This page documents the routine PDAF_set_comm_pdaf of PDAF, which was introduced with PDAF V2.0.

By default, PDAF bases on MPI_COMM_WORLD, thus all processes in a program. This routine allows to set a different communicator. This can be useful if a model is e.g. run with an OI-server so that the world communicator is split into processes for the IO (file) operations and other processes for the actual model run. In this casem, the model would run using a communicator distinct from MPI_COMM_WORLD and PDAF should operate only with this communicator. PDAF_set_comm_pdaf allows the user to specify this communicator for PDAF.

The interface is the following:

SUBROUTINE PDAF_set_comm_pdaf(comm_pdaf)

  INTEGER,INTENT(in) :: comm_pdaf    ! MPI communicator for PDAF

Notes:

  • comm_pdaf has to be used consistently in init_parallel_pdaf where the commuicators for PDAF are prepared on the user side.
  • The size of comm_pdaf has to be large enough so that the ensemble run can be performed
  • PDAF_set_comm_pdaf has to be called before calling PDAF_init