How can I store vectors from three loops?

Hello everyone,

I'm running into this problem in my code where I have three for loops within each other and I would like to save the results as a function of all three loop variables. I have not been able to figure out how to do that. Below is a sample code of what I have in order to show the problem more clearly than my phrasing of the question. In the example below, I'm trying to save d as a function of i, j, and k. I tried doing d(i,j,k), but that doesn't work.

for i = 1:10
   for j = 2:30
     for k = 3:50
         a = 10*i;
         b = 20*j*i;
         c = 40*k;
         d = a*b/c;
     end
    end
end

I really appreciate your help! Thanks!

Answer 1

[dpb]

Sure it works, just write d(i,j,k)

But, since Matlab doesn't allow for starting arrays with lower indices other than 1, you'll have two empty planes and a column of zeros besides the actual numeric values.

The Matlab way would be

[x1,x2,x3] = ndgrid(1:10, 2:30, 3:50);
d=5.*x1.*x2./*x3;

The '5' is 10*20/40 in a consolidation of the constants.

doc ndgrid % for the details

Answer 2

[Azzi Abdelmalek]

[a,b,c,d]=deal(zeros(10*29*48,1));
p=0;
for i = 1:10
  for j = 2:30
      for k = 3:50
          p=p+1;
          a(p) = 10*i;
          b(p) = 20*j*i;
          c(p) = 40*k;
          d(p) = a(p)*b(p)/c(p);
      end
  end
end

Answer 3

[Sari Mira]

Thank you both for your help!

Azzi, unfortunately, the code you sent me ended up making an infinite loop. I tried just running exactly the code you sent, but I just got the infinite loop.

dpb, I'll try that because what I am trying to do is to create a mesh grid with the resulted data.

[dpb]

_...Azzi, ... the code you sent me ended up making an infinite loop...

??? It (presuming you mean the posted code) is simply three counted loops. Simply impossible to be an infinite loop.