Extract variable from function after using parfeval

Question

Koren Murphy 2022-8-12

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1778275-extract-variable-from-function-after-using-parfeval

评论： Raymond Norris 2022-8-16

I am running the following:

fcn=@(i) run("test"+i);
for K=1:4
    F(K)=parfeval(fcn,0,K);
end;

where "test"+i is a script solving to pricude results in matrix format.

I would like to be able to see this matrix after the worker has finished.

I have tried setting the cript as a fucntion and having an outout:

function [Result1]= test1

however I still get no data out of this after using fetchOutputs.

How can i get the variable I require after parfeval has finished?

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Abderrahim. B 2022-8-12

Did you check if the worker has finished the processing?

Koren Murphy 2022-8-12

Yes it has

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Answer 1

Raymond Norris 2022-8-12

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1778275-extract-variable-from-function-after-using-parfeval#answer_1025720

在 MATLAB Online 中打开

@Koren Murphy the issue is that you've told MATLAB there are no output arguments (even if there are)

F(K)=parfeval(fcn,0,K);

The "0" is the number of output arguments. Change this appropriately. For instance

for idx = 1:10
    f(idx) = parfeval(@rand,1,idx);
end
% Now fetch the results
for idx = 1:10
    [idx, value] = fetchNext(f);
    R{idx} = value;
end

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Koren Murphy 2022-8-16

在 MATLAB Online 中打开

fcn=@(i) run("test_"+i);
for idx = 1:4
    f(idx) = parfeval(fcn,1,idx);
end
% Now fetch the results
for idx = 1:4
    [idx, value] = fetchNext(f);
    R{idx} = value;
end

I know have this with fucntions defiend as

function [testRes1]= test_1

However, i now get this error....

Error using parallel.FevalFuture/fetchNext
The function evaluation completed with an error.
Error in EFM_MILP_Parallel_DataSetUp (line 43)
[idx, value] = fetchNext(f);
Caused by:
Error using EFM_MILP_Parallel_DataSetUp>@(i)run("EFMLoop_"+i)
Too many output arguments.