valid indices for 'output' are restricted in parfor loop

Question

soepblik 2021-3-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/761071-valid-indices-for-output-are-restricted-in-parfor-loop

编辑： soepblik 2021-3-3

采纳的回答： Walter Roberson

在 MATLAB Online 中打开

Hi,

i have the following code:

for j= 1:100
    SNR =  list(j);
parfor i = 1:1000
    tot = (j-1)*1000+i;
    totallist(tot,1) = SNR;
    output(tot,1) = awgn(input(tot,1),SNR);
end
end

tot is just the total counter of the full loop

so the full loop contains 100*1000 values.

But why is the output(tot,1) and totallist(tot,1) forbidden?

How can i do it on another way?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2021-3-3

3
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/761071-valid-indices-for-output-are-restricted-in-parfor-loop#answer_637691

在 MATLAB Online 中打开

for j= 1:100
    SNR =  list(j);
    base = (j-1)*1000;
    parfor i = 1:1000
        totallist(base+i,1) = SNR;
        output(base+i,1) = awgn(input(base+i,1),SNR);
    end
end

https://www.mathworks.com/help/parallel-computing/sliced-variable.html

"Form of Indexing. Within the first-level of indexing for a sliced variable, exactly one indexing expression is of the form i, i+k, i-k, or k+i. The index i is the loop variable and k is a scalar integer constant or a simple (non-indexed) broadcast variable. Every other indexing expression is a positive integer constant, a simple (non-indexed) broadcast variable, a nested for-loop index variable, colon, or end."