title: How to create a list of arbitrarily sized lists
body: <p>I'm trying to create a container that has 3 lists within it, where each list is an arbitrarily sized list of arbitrarily sized lists.  Here is my train of thought on what I would be doing (not very experienced in Matlab, so there's probably a more elegant way of doing this)</p>
  
  <pre><code>my_data = [[] [] []];
  
  for m = 1 : M
     list1 = [];
     list2 = [];
     list3 = [];
  
     for n = 1 : N
        if something holds
           list1 = [list1 ftn(n)];
           list2 = [list2 ftn2(n)];
           list3 = [list3 ftn3(n)];
        end
     end
  
     if something else holds
        my_data(1) = [my_data(1) list1];
        my_data(2) = [my_data(2) list2];
        my_data(3) = [my_data(3) list3];
     end
  end
  </code></pre>
  
  <p>This code doesn't actually run though... How do I do something like this in Matlab?</p>