[Paraview] How to get a field value (single scalar) into the calculator tool

[Dan Goldstein]

HI,

   Does anyone know a way to get the value of a field variable at a 
specific point in the field accessible as a scalar in the Calculator tool?

   What I am trying to do is subtract a non-stationary background field 
from the solution of a simulation (velocity) at each time step. What I 
have is a half channel flow type geometry (with some other bumps). The 
inflow is an oscillating boundary layer flow. I would like to be able to 
subtract the inflow velocity in the stream-wise direction from the 
instantaneous flow at each time step so I can visualize a perturbation 
velocity. If I have the inflow velocity at a given height I can 
reconstruct the inflow velocity by height with the calculator tool.

   Ok, so I can use a probe tool to get the value in the field, but the 
probe tool does not seem to output the value to other tools (such as a 
calculator tool).

   Does anyone have any suggestions of how to do this?


   Thanks

Dan