LAM/MPI General User's Mailing List Archives

From: Hugh Merz (merz_at_[hidden])
Date: 2005-11-15 13:43:52

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> MPI::COMM_WORLD.Reduce(&mypi, &pi, 1, MPI::DOUBLE, MPI::SUM, 0);
> --
> A I have a simple question : in this case, results are combined (reduced) on all the computers ?

No, the reduced result only exists on the process whose rank is specified
as the root process, which is 0 in this case.

See:
  http://www.mpi-forum.org/docs/mpi-11-html/node77.html#Node77

Hugh

• Next message: Joshua Mora: "Re: LAM: help with LAM over IB"
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• In reply to: Mathieu FREMONT: "LAM: Reduce() calculation done on every computer ?"