probeLocations, data of patch?point?cell?
 

Dear everyone, I recently use foam-extend-3.1 to simulate fluid-structure interaction problem, and I met a little problem when add functions/probes/probeLocations to controlDict file (to probe pressure field and solid displacement field); the location where data should be acquired is
(0.5 0.5 0)
(0.5 0.5 0.5)
(0.5 0.5 1)
(0.5 0.5 1.003)
(0.5 0.5 2.003)
(0 0 0)
(0 0 2.003),
but the data were wrong, and when changed to locations that are near these points, changing (0.5 0.5 0) to (0.499 0.499 0.001) for example, it seems to work. I went through the probe.C file and it can probe data on patch, cell, and point in my point of view. So I was wondering which one it is (patch, cell, and point) that this function works on.

Functions in controlDict file are listed below.
functions
(
probes
{
// Type of functionObject
type probes;

// Where to load it from (if not already in solver)
functionObjectLibs ("libsampling.so");
region region0;
// Additional entries for OF 1.6.x
enabled true;
outputControl timeStep;
outputInterval 1;

// Locations to be probed. runTime modifiable!
probeLocations
(
/* (0.499 0.499 0.001)
(0.499 0.499 0.499)
(0.499 0.499 0.99)
(0.499 0.499 1.004)
(0.499 0.499 2.002)
(0.001 0.001 0.001)
(0.001 0.001 2.002)
*/
(0.5 0.5 0)
(0.5 0.5 0.5)
(0.5 0.5 1)
(0.5 0.5 1.003)
(0.5 0.5 2.003)
(0 0 0)
(0 0 2.003)
);

// Fields to be probed. runTime modifiable!
fields
(
p
);
}

probes_solid
{
// Type of functionObject
type probes;

// Where to load it from (if not already in solver)
//functionObjectLibs ("libsampling.so");
region solid;
// Additional entries for OF 1.6.x
enabled true;
outputControl timeStep;
outputInterval 1;

// Locations to be probed. runTime modifiable!
probeLocations
(
// (0.49 0.49 1.002)
(0.5 0.5 1.003)
);

// Fields to be probed. runTime modifiable!
fields
(
Usolid
);
}
);


The pressure field when using the previous locations, please that in figure1;
The pressure field when using the latter locations, please that in figure2;