Using parallel.pool.constant with parfeval

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?

Answer 1

[Edric Ellis]

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