HELP! All combinations of array of vectors

Hello to everyone, thanks for your attention.

I quite new in Matlab programming, i am trying to figure out something without success, hope you can help!

So i have a an array of Ni elements and each element is a 5 values vector. it looks like this:

• N1) 0.588 8.102 0.001 0.010 0.002
• N2) 0.588 8.102 0.001 0.003 0.002
• N3) 0.588 8.102 0.006 0.001 0.005...Ni

My code process this N elements array. Among other outputs it gives an error estimation of using these values.

What i would like to do is to is the code to process all possible combinations of elements values till the error is minimized.

So for example, using N1, N2

                      N2, N3
                      .
                      .
                      N1, N2, N3
                      N2, N3, N4
                      .
 And so on, so all possible combinations among the Ni elements varying also the number elements in the combination.

I am sorry i have not been that clear, i did my best, let me know if further information is needed. Hope you can help, i really need some! I would extremely appreciate.

Best regards Emiliano

Answer 1

[pfb]

If I get your problem right, you could use "combnk"

If V is a vector with the indices of your N's, e.g.

 V = 1:10

then

 combnk(V,3)

gives a matrix whose rows are the combinations of 3 indices taken out of V. So, your code might be something like this

 L = 10; % number of N
 V = 1:L;
 for n = 1:L

 C = combnk(V,n); % this is a matrix
 % loop over its rows
   for r = 1:size(C,1)
     c = C(r,:); % this is one particular combination of n elements

     % <<< here you do whatever calculation you need to do based on c 
   end

 end

By the way, since each N has 5 entries, it could be worth forming a Lx5 matrix Nm out of it. This way

 Nm(c,:)

should contain only the values you need for your calculation with the particular combination in c.

[Emiliano Cimoli]

Thanks man i am going to try it out and let you know!, sorry for the really late reply!