[Paraview] integrate flow over line

[Martijn]

Hi,
This week I discovered ParaView and I am impressed (and a little
intimidated) by its possibilities.
A question: is a 2D equivalent of the "Surface Flow" filter? I have a
small 2D thermal simulation and would like to caluclated the flow over a
boundary: int (dT/dx, dT/dy)*n dl.

with kind regards,

Martijn