Hi Jelena,
int* ttt = (int*)malloc(2 * sizeof(int));
ttt[0] = myworldrank + 1;
ttt[1] = myworldrank * 2;
if(myworldrank == 0)
MPI_Reduce(MPI_IN_PLACE, ttt, 2, MPI_INT, MPI_SUM, 0,
MPI_COMM_WORLD); //sum all logdetphi from different nodes
else
MPI_Reduce(ttt, NULL, 2, MPI_INT, MPI_SUM,
Hi Anyi,
you are using reduce incorrectly: you cannot use the same buffer as input
and output.
If you want to do operation in place, you must specify "MPI_IN_PLACE"
as send buffer at the root process.
Thus, your code should look something like:
int* ttt = (int*)malloc(2 * sizeof(int
Hi,
I have a code which have a identical vector on each node, I am going to do
the vector sum and return result to root. Such like this,
int* ttt = (int*)malloc(2 * sizeof(int));
ttt[0] = myworldrank + 1;
ttt[1] = myworldrank * 2;
MPI_Allreduce(ttt, ttt, 2, MPI_INT, MPI_SUM, MPI_COMM_
