Boost.MPI: question about documentation of gather()
Hello, I am trying to debug my simple code (gathering of double arrays onto master). and naturally I opened gather online help: http://www.boost.org/doc/libs/1_45_0/doc/html/boost/mpi/gather.html In Parameters section, for 'in_values', it is stating that if gathering arrays of values, 'in_values' should be pointing to a storage of n*comm.size() values Shouldn't this be n*size_of(T) or something in those lines? Am I missing some obvious points here ? thanks in advance, Hamid
Hi,
On Sun, Dec 12, 2010 at 8:29 AM, H Magnet
I am trying to debug my simple code (gathering of double arrays onto master). and naturally I opened gather online help:
http://www.boost.org/doc/libs/1_45_0/doc/html/boost/mpi/gather.html
In Parameters section, for 'in_values', it is stating that if gathering arrays of values, 'in_values' should be pointing to a storage of n*comm.size() values
Shouldn't this be n*size_of(T) or something in those lines?
Good catch. I think that phrase actually belongs in the "out_values" description, and accidentally slipped into the "in_values" one. For gathering arrays, "out_values" should point to a storage of n*comm.size() values == comm.size() * n * sizeof(T) bytes, because you're receiving n values from each rank. "in_values" should always point to n values == n * sizeof(T) bytes. Best regards, Riccardo
participants (2)
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H Magnet -
Riccardo Murri