[mpich-discuss] gather, send

[Ryan Crocker]

that's where i checked it with and it's min and max are still zero.  I just amended it so that each send buffer from the different cores are the same size and when i check it on the root gsend_buffer is still incorrect.

On May 1, 2013, at 5:00 PM, Rajeev Thakur wrote:

> gsend_buffer will be valid only on the root.
> 
> On May 1, 2013, at 6:55 PM, Ryan Crocker wrote:
> 
>> I just looked at the gsend_buffer, that's actually all zeros as well, and each send_buffer is not.  So i think my problem is there.
>> 
>> On May 1, 2013, at 4:47 PM, Rajeev Thakur wrote:
>> 
>>> The count passed to MPI_Scatter should be the local size, i.e., the amount that gets sent to each process. Looks like what is being passed is the global size.
>>> 
>>> On May 1, 2013, at 6:21 PM, Ryan Crocker wrote:
>>> 
>>>> Hi all, 
>>>> 
>>>> So i don't know what the issue with this code snippet is but i cannot get the scatter call to work.  When i print out the recieve_buffer it comes out as all zeros.   The counters without the underscore are the core domains, with the o, the global domains.
>>>> 
>>>> rec_count  = (imaxo-imino+1)*(jmaxo-jmino+1)*(kmaxo-kmino+1) 
>>>> send_count = (imax_-imin_+1)*(jmax_-jmin_+1)*(kmax_-kmin_+1) 
>>>> 
>>>> call MPI_GATHER  (send_buffer, send_count, MPI_REAL, gsend_buffer, send_count, MPI_REAL, iroot, comm, ierr)
>>>> 
>>>> rec_count  = (imaxo-imino+1)*(jmaxo-jmino+1)*(kmaxo-kmino+1) 
>>>> send_count = (imaxo-imino+1)*(jmaxo-jmino+1)*(kmaxo-kmino+1) 
>>>> 
>>>> call MPI_SCATTER (gsend_buffer, send_count, MPI_REAL, recieve_buffer, rec_count, MPI_REAL, iroot, comm, ierr)
>>>> 
>>>> thanks for the help.
>>>> 
>>>> Ryan Crocker
>>>> University of Vermont, School of Engineering
>>>> Mechanical Engineering Department
>>>> rcrocker at uvm.edu
>>>> 
>>>> 
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>> 
>> Ryan Crocker
>> University of Vermont, School of Engineering
>> Mechanical Engineering Department
>> rcrocker at uvm.edu
>> 315-212-7331
>> 
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> 
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Ryan Crocker
University of Vermont, School of Engineering
Mechanical Engineering Department
rcrocker at uvm.edu
315-212-7331