Computing a Flux Integral in Paraview

I am currently looking into post-processing of simulation data using Paraview. I would like to compute certain integrals of field quantities. As an example, consider the following surface integral of an electric field in a simple situation:

$$\iint_{S}^{} \vec{E}\cdot\vec{\omega}=\Phi$$

The surface $$S$$ is shown in the following picture:

I can define a surface in ParaView and I can compute the surface normals $$\vec{w}$$ (white arrows in he picture). In order to compute the integral in question, I guess I would have to use a calculator to compute $$\vec{E}\cdot\vec{\omega}$$ and then use the "Integrate Variables" Filter.

My problem is, that I can only add the calculator to the "case0001.vtu tree" or the "plane tree" in the pipeline browser such that it's impossible to select both the vectors "electric fields" and "normals" in the calculator to compute the integrand $$\vec{E}\cdot\vec{\omega}$$.

Does anyone know how I could use a calculator to compute the integrand in Paraview?

• You need to make plane dependent on electric_field. – nicoguaro Jan 15 at 1:07