Applying the invariant approximations to the analysis of electromagnetic fields

This report deals with the elaboration of general algorithms for constructing discrete analogies of differential boundary-value electromagnetic problems by means of the finite-difference method and the theory of invariant function approximation. The obtained analogies are invariant according to the group of linear transformations of the Cartesian co-ordinate system, conservative and independent from the configuration of boundary and contact surfaces. They are characterized by the prescribed order of accuracy.