For loop with 2 variables

Hi,

Hi, I'm looking for an idea on how to iterate all possible combinations for the couple using the for loop, to apply the parfor loop in my code.

for example

without using the for loop twice:

for i =1:N
    parfor j =1:N
        .......
    end 
end

[Matt J]

It would be advisable to show us the computation you are doing in more detail, so we might recommend alternatives. Matlab already has lots of builtin functions for iterating over grids. You may not need to use a loop at all.

[B.E.]

%% The Code used is:
Y_1 =zeros(N,numel(alpha),numel(beta));
Y_2 =zeros(N,numel(alpha),numel(beta));
for i = 1:numel(alpha)
    parfor j =1:numel(beta)
        [Y_1(:,i,j),Y_2(:,i,j)] = My_Fun(alpha(i),beta(j),......)
    end  
end

[Matt J]

That doesn't really give us any information. All of the details of your computation are hidden inside My_Fun().

Answer 1

[Matt J]

    parfor k =1:N^2
        [i,j]=ind2sub([N,N],k);
        ....
    end 

[B.E.]

Thank you very much,

I have this error for my code

Y_1 =zeros(N,numel(alpha),numel(beta));
Y_2 =zeros(N,numel(alpha),numel(beta));
parfor k =1:numel(alpha)*numel(beta)
        [i,j]=ind2sub([numel(alpha),numel(beta)],k);
        [Y_1(:,i,j),Y_2(:,i,j)] = My_Fun(alpha(i),beta(j),..); 
end

the parfor loop cannot run due to the way variable 'Y_1' is used

the parfor loop cannot run due to the way variable 'Y_2' is used

[Matt J]

The 3D structure of your Y_1 and Y_2 arrays are irrelevant to what's happening in the loop. You can just do,

Y_1 =zeros(N,numel(alpha),numel(beta));
Y_2 =zeros(N,numel(alpha),numel(beta));

parfor k =1:numel(alpha)*numel(beta)
        [i,j]=ind2sub([numel(alpha),numel(beta)],k);
        [Y_1(:,k),Y_2(:,k)] = My_Fun(alpha(i),beta(j),..); 
end

[B.E.]

The problem is solved.

Thank you so much Matt J

[B.E.]

Hi Matt J,

My code is executed normally without the parfor command i.e with the for command.

If I reduce the numbre of cores to 4, my code will run normally with the parfor command.

Can you help me this is urgent.

Thank you again for your help.