restriction

emg3d.solver.restriction(model, sfield, residual, sc_dir)

Downsampling of grid, model, and fields to a coarser grid.

The restriction of the residual is used as source term for the coarse grid.

Corresponds to Equations 8 and 9 and surrounding text in [Muld06]. In the case of the restriction of the residual, this function is a wrapper for the jitted functions emg3d.core.restrict_weights and emg3d.core.restrict (consult these functions for more details and corresponding theory).

This function is called by emg3d.solver.multigrid.

Parameters:

modelVolumeModel

Input model; a emg3d.models.Model instance.

sfieldField

Input source field; a emg3d.fields.Field instance.

sc_dirint

Direction of semicoarsening.

Returns:

cmodelVolumeModel

Coarse model.

csfieldField

Coarse source field. Corresponds to restriction of fine-grid residual.

cefieldField

Coarse electric field, complex zeroes.