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Bill Barth
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Your MPI_ReduceMPI_Reduce call doesn't have a valid communicator specified. I think you left it out entirely. The place where you have rank should be the same value everywhere you call it, and it should be a communicator. From the look of your code, it should be MPI_COMM_WORLD since every rank is doing the operation.

Bill Barth
• 10.7k
• 1
• 19
• 38

Your MPI_Reduce call doesn't have a communicator specified. I think you left it out entirely. The place where you have rank should be the same value everywhere you call it, and it should be a communicator. From the look of your code, it should be MPI_COMM_WORLD since every rank is doing the operation.