Question on updating a matrix

I have to create an adjacency matrix every time an if condition is satisfied. I've written the following code.

if ~isempty  (Xnew{k,i})
for ii = 1:n
    for jj = 1:n
      L(ii,jj) = any(ismember(Sc{ii,jj},Xnew{k,i}));
      if L(ii,jj) == 1
            seccost(ii,jj)  = costs(ii,jj);
        else 
             seccost(ii,jj)  = 0;
    end
    end
end

It means that if my set Xnew is empty and if L(ii,jj) is true, then I've to create an adjacency matrix seccost with index ii,jj having some value costs(ii,jj). If L(ii,jj) = 0, the seccost(ii,jj) = 0.

This would be a great code if the size of n is small. But I've a huge value for n and if condition is incurred many times. while creating L, matlab is running out of memory. Please help!!

[Amit]

How big is n?

[Jan]

Please post the error message.

[jana]

Thank you Jan, I fixed the error. @ Amit, n is 4000..basically n represents the number of nodes.

Answer 1

[Jan]

Did you pre-allocate L and seccost before the loop?

L = false(n, n);
seccost = zeros(n, n);

[jana]

Yes, but it is still not helping.