Definition
MPI_Group_rank gets the rank of the calling MPI process in the group given.
int MPI_Group_rank(MPI_Group group,
int* rank);
Topology
C | Fortran-2008 | Fortran-90
MPI_Group_rank
Parameters
- group
The MPI group to explore.
- rank
A pointer on the variable in which write the rank of the calling MPI process in the MPI group given.
Return value
The error code returned from the group rank retrieval.
- MPI_SUCCESS: the routine successfully completed.
Example
#include <stdio.h>
#include <stdlib.h>
#include <mpi.h>
/**
* @brief For each process in the group of the default communicator
* MPI_COMM_WORLD, show their rank.
**/
int main(int argc, char* argv[])
{
MPI_Init(&argc, &argv);
// Get the group of processes from the default communicator
MPI_Group group;
MPI_Comm_group(MPI_COMM_WORLD, &group);
// Get my rank in that group.
int my_rank;
MPI_Group_rank(group, &my_rank);
// Print my rank in that group.
printf("I am MPI process %d in the group.\n", my_rank);
MPI_Finalize();
return EXIT_SUCCESS;
}