emg3d.solver.prolongation(efield, cefield, sc_dir)[source]

Interpolating the electric field from coarse grid to fine grid.

The prolongation from a coarser to a finer grid is the inverse process of the restriction (emg3d.solver.restriction) from a finer to a coarser grid. The interpolated values of the coarse grid electric field are added to the fine grid electric field, in-place. Piecewise constant interpolation is used in the direction of the field, and bilinear interpolation in the other two directions. See Equation 10 in [Muld06] and surrounding text. Perfect Electric Conductor (PEC) boundary condition is enforced in this step.

This function is called by emg3d.solver.multigrid.

efield, cefieldField

Fine and coarse grid electric fields, emg3d.fields.Field instances.


Direction of semicoarsening.