Extracting data from handle objects

Hey, I have following problem.

I have multiple handle class objects which all have a propertie which can either be a scalar or a vector/matrix.

I now need a way to extract the last values of those vactors/matrices from all objects, so that they form a vector again.

So for example:

obj(1).value1=[1,2,3];
obj(1).value2=[0,0,0;0.1,0.2,0.3;0.9,0.8,0.7];
obj(2).value1=[1,2,3,4,5];
obj(2).value2=[0,0,0,0,0;0.9,0.7,0.8,0.6,0.5;0.1,0.2,0.3,0.4,0.5];
...

I now need to extract the data like

value1_vector=[3,5];
value2_vector=[0,0.3,0.7;0,0.5,0.5];

At the same time, these vectors/matrices have no fixed length and I dont know the length at the start. So it would be better to save same as a cell? Would that make the extracting of the values above easier?

Maybe a change in the size is not preferable when in future the code might be tranfered to a mexfile, where a size change while runtime is inmpossible.

Many thanks in advance

[Catalytic]

Strangely, it appears that you have asked 52 questions, but accepted answers to only 1 of them. Have you truly had such poor luck in getting useful answers?

[Marc Laub]

Did my best to trace back the most valuable answers, except if the answer was within a comment...

[Rik]

The best strategy for storing your data depends on what you want to do next.

Do not reject a solution with a loop out of hand. Loops are fast and are easy for Matlab (or a human) to translate to C(++).

Answer 1

[Askic V]

I hope this helps a bit:

clear
clc

obj_arr = struct('value1',[], 'value2',[]);
rng(0)
% Initialize obj_array
for ii = 1:2
    % generate random number of elements 
    nr_el = randi([2 6], 1,1);
    obj_arr(ii).value1 = randi(10,1,nr_el);
    obj_arr(ii).value2 = randn(nr_el,nr_el);
end

% Determine the size of obj_arr
N = length(obj_arr);
% vectors to store values
value1_vec = zeros(1, N);
value2_vec = [];
for ii = 1:N
    value1_vec(ii) = obj_arr(ii).value1(end);
    [r2, c2] = size(obj_arr(ii).value2);
    for jj = 1:r2
        value2_vec = [value2_vec, obj_arr(ii).value2(jj,c2)];
    end
end
value1_vec

value1_vec = 1×2

3 8

value2_vec

value2_vec = 1×11

-0.7549 1.3703 -1.7115 -0.1022 -0.2414 0.3192 2.3505 -0.6156 0.7481 -0.1924 0.8886