Writing a shared variable at the end of a parfor loop

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Mark
Mark 2012-3-21
Hi,
I am using the parfor construct in Matlab. I need each worker to perform certain work and put the result in a matrix. Then I need to join together all the matrices into one. Something like in the pseudo code below
The idea is that each lab can perform a lot of computations and update its own result matrix, but at the end I want to join all the matrices together. There is no need to update the final matrix every time a lab does a computation.
EDIT: prefer a Matlab solution rather than a file exchange contribution
Thanks in advance
mat_for_all = [];
mat_local = [];
parfor i=1:100000
result = do_some_calc(i);
mat_local = [mat_local; result];
end
% join all the local matrices:
mat_for_all = [mat_for_all; mat_local];

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Thomas
Thomas 2012-3-21
This mat_for _all will have results of all the iteration in it, to check the result of each iteration use: mat_for_all(iteration_no). Dunno, where you are getting stuck..
mat_for_all=[];
parfor i=1:10000
mat_for_all(i)=randn;
end
mat_for_all
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Thomas
Thomas 2012-3-22
The above parfor loop does work.. and MATLAB does the concatenation of the matrices.. That is the way the parallel computing toolbox has been designed and the there is little to no penalty for writing the elements of the matrix that way (Due to something internal in the PCT ..) I have run Monte Carlo simulations with thousand of runs the above way and it works fine..

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