MATLAB: Using parallel.pool.constant with parfeval

parallel.pool.constantparfeval

I've got large constant topological matrixes, I want to work with in parallel. I'm trying to find out how parfeval work's with a parallel.pool.constant. It's mentioned that it works on http://de.mathworks.com/help/distcomp/parallel.pool.constant.html
Here is my Test_Script.m:
Test = 1;
Testp = parallel.pool.Constant(Test) 
for ab = 1:2 
     F(ab) = parfeval(@Test2,1); 
end 
parfor ab = 1:2 
    x(ab,:) = Testp.Value; 
end
The function Test2.m ist only
function [out]=Test2() 
    out = Testp.Value 
end
So the parfor-loop works, but the parfeval-loop says, that "Undefined variable "Testp" or class "Testp.Value"." Can you tell me, how it works?

Best Answer

You need to explicitly pass the instance of parallel.pool.Constant into your parfeval call - it doesn't work like a global variable - it works more like an ordinary variable, but with some behind-the-scenes intelligence to minimise data transfers. So, here's what you'd need to change:
% In your script:
...
    F(ab) = parfeval(@Test2, 1, Testp);
...
% In Test2.m:
function [out] = Test2(inConst)
    out = inConst.Value; 
end
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