how to generalize a nested for-loop?

Hello all,

Per my earlier question in http://www.mathworks.com/matlabcentral/answers/252008-a-simpler-way-of-doing-a-nested-loop

Is there a way to generalize that nested loop so that it works for any sizes of V? Thank you.

Answer 1

[per isakson]

Try

>> tic, for ii = 1:5000, h1 = cssm( 4 ); end, toc
Elapsed time is 0.279794 seconds.
>> tic, for ii = 1:5000, h1 = cssm( 6 ); end, toc
Elapsed time is 0.950556 seconds.

where

function    h1 = cssm( N )
    % V = [1+1i, 1-1i, -1+1i, -1-1i];
    V = rand(1,N)+1i*rand(1,N);
    n = length(V);
    h1 = zeros(n, n, n, n);
    for m1 = 1:n
        c = 0.3 * V(m1);
        for m2 = 1:n
            c = c + 0.2 * V(m2);
            for m3 = 1:n
                c = c + 0.5 * V(m3);
                for m4 = 1:n
                    h1(m1,m2,m3,m4) = c + 0.8 * V(m4);
                end
            end
        end
    end
end

It already works for "any" length of V - or I missed something

[Mnr]

Thank you! It works for any length of V, however, is there a way of generalizing the number of nested loops? In particular, here we have four number of "for" loops as we have h1=zeros(n,n,n,n). what if h1=zeros(n,n,...,n)?

[per isakson]

Don't know, however you wrote "works for any sizes of V?"

[Mnr]

Sorry, I should have asked more clearly.