sampling Data during calculation
 

Hi There!

right about now i'm struggling a bit with the Data sampling via functionObject in the controlDict.

I created the following sampling dictionary in controlDict

sampling
{
type sets;
functionObjectLibs ("libfieldFunctionObjects.so");
outputControl timeStep;
outputInterval 0;

interpolationScheme cellPoint;
setFormat raw;

sets
(
testLine
{
type uniform;
axis y;
start ( -0.015 0.095 0.005 );
end ( -0.015 0.095 0.03 );
nPoints 100;
}
);
surfaces();
fields (U.component(0));
}

to sample Values along a line.
Ist does something, but not sampling the line. Actually it writes a particleCloud, which is empty

So my Question is, what did I do wrong, or how to sample Values along a line during calculation via functionObject in the controlDict.

Thanks for any Ideas and greetz
Jim

p.s.: Sampling stuff is discriped here:
http://www.openfoam.com/docs/user/sample.php