Cartesian Topology
Virtual and Physical Topologies
#include<mpi.h>
#include<stdio.h>
/* A 12 process- 2 Dimensional Cylinder*/
#define TRUE 1
#define FALSE 0
int main(int argc, char *argv[]) {
MPI_Status status;
int rank;
MPI_Comm A_New_MPI_World;
int dim[2],reorder,period[2];
int up,down,right,left;
MPI_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD,&rank);
dim[0]=4; dim[1]=3;
period[0]=TRUE; period[1]=FALSE;
reorder=TRUE; /* Can the processes be reordered, may result in improved performance.*/
MPI_Cart_create(MPI_COMM_WORLD,2,dim,period,reorder,&A_New_MPI_World);
MPI_Cart_shift(A_New_MPI_World,0,1,&left,&right);
MPI_Cart_shift(A_New_MPI_World,1,1,&up,&down);
printf("Task: %i My neighbors are u: %i d:%i 1:%i r:%i\n",rank,up,down,left,right);
MPI_Finalize();
}
