Why does "parsim" or "batchsim" with a postSimFcn that accepts a SimulationInput cause an "out of memory error during serialization" error?

I am attempting to run simulations using "parsim" or "batchsim". I notice that the simulations take up an extraordinarily large amount of memory, significantly more than what would be expected from their input and output data. Then I receive the error:

 "out of memory during serialization"

Answer 1

[MathWorks Support Team]

The issue is triggered by passing a SimulationInput object as an argument to a postSimFcn:

>>SimIn(idx) = SimIn(idx).setPostSimFcn(@(x) postsim(x, SimIn(idx)));

Using the SimulationInput object as an input argument of the anonymous function in this callback can cause a circular reference which led to runaway memory usage during the serialization of parsim and batchsim initialization.

In R2024a and later releases, parsim and batchsim can automatically pass the SimulationInput as a second argument on its call to your postSimFcn. See argument "y" in the pseudocode below. This syntax will avoid this problem. 

>>simIn = setPostSimFcn(simIn,@(x,y) postsim(x,y)); 
function new_out = postsim(curr_out,curr_in)

    %your code here


end

In earlier releases, a workaround is to use a temporary variable for the SimIn element instead of passing the simulation input object itself.

>>tmpSimIn = SimIn(idx);>>SimIn(idx) = SimIn(idx).setPostSimFcn(@(x) postsim(x, tmpSimIn));