BUG : Wrong interpolation by fenics for probes

[KikeM]

I am implementing a linear interpolation between nodal values to compare FOM and ROM solutions.

Since I had already implemented a probe interpolation using the fenics __call__ method for CoefficientFunctions, I expected my interpolation to match these values.

To my surprise, they don't.
In fact, they do at the outflow (which is reassuring although trivial. Reassuring because the mass conservation calculation uses this value; trivial because it is a nodal value, so no interpolation takes place.), but they don't at the mid-point x=0.5.

I think there might be a problem with the moving mesh and the interpolation routine used inside fenics.
I am going to stick to my interpolation and use it to compare FOM and ROM solutions.

legend:

• dashed: expected value.
• cont.: interpolation.

[KikeM]

Closed with #35