A decimated version of a broad family of Finite-Difference Time-Domain schemes is derived by an algebraic rearrangement of their matrix formulation, allowing for computing the grid nodes at half the temporal steps compared to the original scheme. This rearrangement can ask for solving a generalized matrix inversion problem. The decimated scheme generates solutions having comparable accuracy to that exhibited by the original simulations. However, the broader applicability of the proposed technique requires to solve currently unanswered theoretical issues of spatial grid decimation, as well as to make extensive tests using large matrices.
