Hello Everyone,
I am new to this group. I got error when I try to write down a mpi point to point program. Here is my program.
#include <stdio.h>
#include <math.h>
#include<mpi.h>
double sum(int n);
int main(void){
int my_rank,comm_sz, n=1024;
double local_sum, total_sum;
int source;
int local_n;
MPI_Init(NULL,NULL);
MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
MPI_Comm_size(MPI_COMM_WORLD, &comm_sz);
local_n=comm_sz/n;
local_sum=sum(local_n);
if ( my_rank != 0) {
MPI_Send (&local_sum , 1, MPI_DOUBLE , 0, 0, MPI_COMM_WORLD ) ;
}
else{
total_sum = local_sum;
for(source=1;source<comm_sz;source++){
MPI_Recv (&local_sum , 1, MPI_DOUBLE , source , 0, MPI_COMM_WORLD , MPI_STATUS_IGNORE ) ;
total_sum+=local_sum;
}
}
MPI_Finalize();
return 0;
}
double sum(int n){
int i;
double cal_sum=0;
for (i =0;i <= n;i++) {
cal_sum = cal_sum + 4*(pow (-1, i))/((2*i)+1);
}
return cal_sum;
}
I got the error
[node007:73071] *** An error occurred in MPI_Recv
[node007:73071] *** reported by process [2587557889,0]
[node007:73071] *** on communicator MPI_COMM_WORLD
[node007:73071] *** MPI_ERR_RANK: invalid rank
[node007:73071] *** MPI_ERRORS_ARE_FATAL (processes in this communicator will now abort,
[node007:73071] *** and potentially your MPI job)
Can anyone please let me know what logic error there is in my program? I try to run this program for 4 processes.