How to use a parfor loop inside a for loop?

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I have a for loop with variables that have dependency. Within that loop I would like to use parfor to perform a costly operation on a variable that is independent across iterations. Below I made an example; say that I want to perform myFun on each entry in the row (in parallel) corresponding to the iteration of the for-loop.
N = 10;
inputVar = [randi(100,N,1),zeros(N,1)];
out = cell(N,2)
for idx = 1:N
inputVars(idx,2) = idx;
parfor jdx = 1:2
out{jdx,kdx} = myFun(inputVars(jdx,kdx))
end
end
I'm new to parallel computing. Not sure if this example is a good one. I can provide a better example if asked.

Accepted Answer

Walter Roberson
Walter Roberson on 9 Mar 2018
Generally speaking you can do that. However, parfor will have an easier job if you write to an output that is indexed only by the loop index and possibly the : (colon) operator. For example,
temp_input = inputVars(:,kdx);
parfor jdx = 1 : 2
temp_out{jdx} = myfun(temp_input(jdx));
end
out(:,kdx) = temp_out;
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