How to write a for loop with d indexes

I am writing a for loop such like

for i_1 = 1:n_1
    for i_2 = 1:n_2
        ...
            for i_d = 1:n_d
            
            end
    end
end

How can I do this correctly? Thanks very much!

[Stephen23]

https://www.mathworks.com/matlabcentral/answers/79986-how-can-i-condition-the-number-of-nested-for-loops-in-a-function-on-an-input-argument

https://www.mathworks.com/matlabcentral/answers/345551-function-with-varying-number-of-for-loops

https://www.mathworks.com/matlabcentral/answers/381505-creating-a-variable-number-of-nested-for-loops

https://www.mathworks.com/matlabcentral/answers/39881-create-a-variable-number-of-nested-for-loops-select-elements-in-matrix-with-variables-dimensions

Answer 1

[Jan]

This is the code for 5 nested loops, but you set set d dynamically as you want:

nLoop = 5;                   % Number of loops, set as you want
n1=1; n2=2; n3=3; n4=4; n5=5;

ini = [1, 1, 1, 1, 1];       % Initial value
fin = [n1, n2, n3, n4, n5];  % Final value of each nested loop

nv     = fin - ini + 1;
Output = cell([nv, 1]);
v      = ini;                % Start with initial values
for k = 1:prod(nv)
   Output{k} = <your calculations here using index vector v>

   % Update the index vector - this emulates nLoop nested loops:
   for iv = 1:nLoop
       if v(iv) < fin(iv)
          v(iv) = v(iv) + 1;
          break;        % v(iv) increased successfully, leave "for iv" loop
      end
      v(iv) = ini(iv);  % v(iv) reached the limit, reset it
   end
end

[Jingyu Liu]

Big thanks!