prolongation

emg3d.solver.prolongation(efield, cefield, sc_dir)

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.

Parameters:

efield, cefieldField

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

sc_dirint

Direction of semicoarsening.