colon operation (:) causes parfor to fail on cell array
조회 수: 1 (최근 30일)
이전 댓글 표시
The following code causes Matlab to throw subscript assignment error:
s=cell(1,20);
parfor i = 1:20
s{:,i}=1;
end
However, when the colon operator is replaced with a 1, there is no error:
s=cell(1,20);
parfor i = 1:20
s{1,i}=1;
end
My guess is this involves a slicing issue somehow. Any insights?
댓글 수: 1
Sergio Santos
2015년 2월 16일
There is a solution to this. Reshaping whatever you want to send to parfor and turning it into a single column or raw vector. Also make a vector to store the length of each vector you reshape. Then when the operation is finished reshape back into matrix form. Shaping and reshaping is very fast and can be fastly done by a single worker, i.e. no need parallel computing.
채택된 답변
추가 답변 (2개)
Cedric
2013년 3월 28일
편집: Cedric
2013년 3월 28일
It has a priori nothing to do with PARFOR; the expression involving the colon on the left hand side is a comma separated list (CSL), so you cannot have the scalar 1 on the right hand side. Try it with a simple FOR loop and there will be no difference.
I don't know exactly what you want to do with that, but I guess that it is something like
s(:,i) = {1} ;
댓글 수: 7
Cedric
2013년 3월 29일
Thank you for the update! I will think about it a bit more about it and perform a few tests on my side.
Ben
2013년 4월 12일
please tell us they working on a patch. i've come across this bug too now in 2013a
댓글 수: 0
참고 항목
카테고리
Help Center 및 File Exchange에서 Parallel for-Loops (parfor)에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!