MATLAB: Assigning handle classes in a parfor loop

handle classesParallel Computing Toolboxparfor

I have been doing some calculations which are output by assigning data to a handle class array. The calculations run fine when I use a for loop but when I try to parallelise this by conversion to a parfor loop, the assigned data are no longer there when the parfor loop ends.
The documentation alludes to this as follows: "Changes made to handle classes on the workers during loop iterations are not automatically propagated to the client."
This implies that it may be possible for such changes to be propagated back, even if it's not done automatically. Does anyone know how I might do this?
Here is some example code:
classdef Example < handle
    properties
        data
    end
    methods
        function obj = Example(data)
            obj.data = data;
        end
        function setData(obj,data)
            obj.data = data;
        end
        function data = getData(obj)
            data = obj.data;
        end
    end
end
Now here is some example code which generates an array of these objects and then assigns values to them in a parfor loop. Finally we look at the values of the data.
% Function to demonstrate use of Example in a parfor loop
function testExample num = 5;
    % Initialise array of objects
    for n = 1:num
        exArray(n) = Example(zeros(1,6));
    end
    % Set data within a parfor loop
    parfor n = 1:num
        setData(exArray(n),n:n+5);
    end
    % Now look at assigned data
    for n = 1:num
        disp(getData(exArray(n)));
    end
end
When I run this code without the matlabpool open, it behaves as expected:
1 2 3 4 5 6
2 3 4 5 6 7
3 4 5 6 7 8
4 5 6 7 8 9
5 6 7 8 9 10
But when I run with matlabpool open, the updated values are lost outside of the parfor loop, giving this result:
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
Does anyone have any idea how to get around this problem, other than by not using parfor?

Best Answer

I have received an answer to this issue from technical support. Apparently the Mathworks regard it as a 'feature' that changes to objects are not returned - though I can't see that it's a very useful feature. Anyway, the way to get modified class properties returned from a parfor loop is to make an explicit change which can be recognised by parfor. Here are two examples which work for the above example object:
    parfor n = 1:num
        exArray(n).data = n:n+5;
    end
or
    parfor n = 1:num
        temp = exArray(n);
        setData(temp,n:n+5);
        exArray(n) = temp;
    end
Actually, if you change any object property it also seems to work. So for example this also works, if there is a second property data2 which is set explicitly, both data and data2 are correctly returned:
      parfor n = 1:num
          setData(exArray(n),n:n+5);
          exArray(n).data2 = n:n+5;
      end
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