To pass a variable outside a parfor loop

Question

George Bashkatov 2021-5-5

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/822500-to-pass-a-variable-outside-a-parfor-loop

编辑： George Bashkatov 2021-5-6

I have a loop that looks like:

parfor j=1:length(P)
for i=1:(length(A)-1)
%unnecessary calculations
for i=1:(length(A)-1)
end
for k=1:(length(B)-1)
ri(k,l)=len(k); %len is a vector, that has been defined already
sr(1,i)=r(i);   %r is a vector, that has been defined already
end
%unnecessary calculations
end
%unnecessary calculations
end
plot(ri,sr); %I know that these two vectors have different dimensions, it's just example to show, that I use variables outside parfor
%loop. By the way, I use the variables in functions "plot" and "meshgrid"

So I tryed to use cell arrays as Walter Roberson recommend:

%in my program (length(A)-1)=40, (length(B)-1) = 10;
ri=cell(10,40); sr=cell(1,40);
parfor j=1:length(P)
for i=1:(length(A)-1)
for k=1:(length(B)-1)
ri{k,l}=len(k); 
sr{1,i}=r(i);   
end
end
end
ri1=cell2mat(ri);
sr1=cell2mat(sr); %last two lines are my own ideas I don't know good or bad
plot(ri1,sr1);

And matlab writes that because of the way of using variables the parfor loop can't be executed. It writes the same as before changing the code.

The main error is "Unable to classify the variable 'ri' in the body of the parfor-loop". Can you help me, please?

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Answer 1

George Bashkatov 2021-5-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/822500-to-pass-a-variable-outside-a-parfor-loop#answer_693530

编辑：George Bashkatov 2021-5-6

在 MATLAB Online 中打开

1) replace (length(A)-1), length(P) and (length(B)-1).

2)make temporary variables lentemp and rtemp

3)add one more index j

4)choose data for plotting

r1=(length(A)-1); r2=length(P); r3=(length(B)-1); %replacing
parfor j=1:r2
for i=1:r1
    rtemp=r; %making temporary variables
for k=1:r3
    lentemp=len; %making temporary variables
ri(k,l,j)=lentemp(k); %adding index
sr(1,i,j)=rtemp(i);   %adding index
end
end
end
plot(ri(:,:,end),sr(:,:,end)); %choosing data