Lists of objects?

[Joanna Rutkowska]

Hello,

What is the best method to create a list of objects (all of the same 
class)? I tried this:

list = [obj1, obj2, obj3];

... but when displaying such a list (the class defines own display() 
method) I can see how the calls to each display () method got screwed 
up, and intermixed, just if there was some race condition problem 
somewhere, e.g.:

octave:2> motors_list

Robbe ROXXY 2827/34 motor:
--------------------------

MK 3638 motor:
--------------------------
 Kv = 760.000000 [RPM/V]
 Kv = 770.000000 [RPM/V]
 Rm = 0.244000 [Ohm]
 Rm = 0.700000 [Ohm]
 I0 = 0.500000 [A]
 I0 = 0.060000 [A]
 mass = 60 [g]
 mass = 132 [g]
 max current (continues) = 9.0 [A]
 max current (continues) = 20.0 [A]
 source: ecalc.ch
 source: Google :)

When I use cell array instead, i.e.:

list = {obj1, obj2, obj3}

... then the display works fine:

octave:2> motors_list
motors_list =
{

Robbe ROXXY 2827/34 motor:
--------------------------
 Kv = 760.000000 [RPM/V]
 Rm = 0.244000 [Ohm]
 I0 = 0.500000 [A]
 mass = 60 [g]
 max current (continues) = 9.0 [A]
 source: ecalc.ch

MK 3638 motor:
--------------------------
 Kv = 770.000000 [RPM/V]
 Rm = 0.700000 [Ohm]
 I0 = 0.060000 [A]
 mass = 132 [g]
 max current (continues) = 20.0 [A]
 source: Google :)
}

Anybody can explain to me why the use of standard array messes up the 
output?

Also, what is the best method to build a list successively, e.g.:

obj1 = xxx ()
list = {list, obj1}

obj2 = xxx ()
list = {list, obj2}

The code above unfortunately doesn't work well, because it creates 
nested cell arrays.

?

Also, what is the best method to create code that would something like that:

list1 = {c1_obj1, c1_obj2, c1_obj3, ...} // all objs of class c1
list2 = {c2_obj1, c2_obj2, ...} // objects of class c2
...
listN = {cN_obj1, cN_obj2, ...} // objects of class cN

Now, for each combination of objects from each list, do something, e.g.:

X = something (list1(i1), list2(i2), ... listN(iN)

In other words, having some N-dimensional space of possible 
configurations, I would like to calculate a target function on each 
possible point in this space.

The most primitive way of coding this would be, of course using the N 
nested for loops, e.g.:

for i1 = 1:lengtt(list1)
 for i2 = 1:length(list2)
  ...
   for iN = 1:length(listN)
        X = something (list1(i1), list(i2), ..., list(iN))

 but I was curious if there is a mechanism in matlab to do that somehow 
nicer?

Thanks,
joanna.