Parfor converting object to double?

I am trying to parallelize some of my code to make it run quicker and ran into a weird error that I get in 2019a but not in 2020b. The error states:

The following error occured converting DataObj to double: Converstion to double from DataObj is not possible.

This doesn't happen when I am running serially with a for loop instead. If I set DataObj.double to output a double, then I get the error Assertion failed in consume_assign at line 24. A simplified version of my code is below.

Why am I seeing this in older versions, and is there a way to fix this to work on older versions?

dataSet = repmat(DataObj.empty(),1,N);
for ii = 1:N
    dataSet(ii) = DataObj(info(N));
end

Answer 1

[Edric Ellis]

In older versions that exhibit the problematic behaviour, your best bet is probably to use a cell, like so:

N = 3;
resultCell = cell(1, N);
parfor i = 1:N
    resultCell{i} = MException('dummy:exception', 'Just for this example');
end
result = [resultCell{:}]

result = 
  1×3 MException array with properties:

    identifier
    message
    cause
    stack
    Correction