Nested for-Loops in parfor
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I try to put a for-loop in a parfor-loop. However, the following code is invalid.
parfor i=1:10
for j=1:10
a(j)=1;
end
end
The only way I know to fix that is
parfor i=1:10
for j=1:10
a(i,j)=1;
end
end
But I think it is inefficient when the size of "a" is large (I don't need "a" at the end of this program) . Is there a better way to implement this nested for-loop?
1 Comment
Edric Ellis
on 23 Mar 2022
@Walter Roberson has provided you with a way to fix the problem. Just to explain the problem a little bit more - parfor insists on being able to prove that the iterations of your parfor loop are not (trying to be) order-dependent. In your original code, it appears as though the value of a as assigned when i==1 is still available on the next iteration when i==2. Walter's fix assigns a value to the whole of a, and this makes parfor satisfied that you cannot possibly access the old values of a in subsequent iterations.
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