1. A method for determining nominal values of at least one electrical parameter for an integrated circuit comprised of a plurality of circuit elements, the method comprising: producing, by a computer, a template which describes physical geometry of a portion of the integrated circuit, wherein the portion of the integrated circuit comprises at least two circuit elements disposed between two layers; producing, by the computer, a grid of nodes for the template, wherein the grid of nodes is disposed in the space between the at least two circuit elements; determining, by the computer, the nominal values of the at least one electrical parameter by using a nominal linear system that comprises a discretized linear system of equations descriptive of an electrical potential at the nodes of the grid of nodes, wherein determining the nominal values of the at least one electrical parameter comprises solving the nominal linear system to obtain a vector of potentials and using the obtained vector of potentials to obtain the nominal values of the at least one electrical parameter; and determining, by the computer, sensitivity values for the at least one electrical parameter by applying an adjoint method to an auxiliary linear system, wherein determining the sensitivity values for the at least one electrical parameter comprises using the obtained vector of potentials, wherein the auxiliary linear system represents a relationship between an auxiliary vector and known relative variation with respect to discretized electrical quantities of the nodes, wherein determining the sensitivity values for the at least one electrical parameter comprises applying a two-step method, wherein the two-step method comprises an iterative procedure for solving finite-difference equations resulting from discretizing Laplace or Poisson partial differential equations in a rectangle.