Add linear interpolator and use it for scaling fields
A linear interpolator takes point values (as opposed to the available nearest-neighbor interpolator which takes cell values) on a regular grid and evaluates the local linear interpolation of the nearest four vertices for any position of the grid.
- Add a linear interpolator with specializations for 2D and 3D.
- Enable using the interpolator for scaling field input.
How to test the implementation?
- Add a unit test for the linear interpolator
- Use it in the unit test for a scaling field