Method and apparatus for costing a path expansion

摘要

Some embodiments of the invention provide a method of propagating a first cost function that is defined over a first state to a second slate in a space representing a design-layout region. In some embodiments, the space includes a set of states and a transition map that specifies a set of states that can be reached from each particular state. The space has several dimensional states. The method identifies several pairs of wedge vectors. Each vector has a tail, and each wedge-vector pair includes two vectors that are connected at their tails. The method assigns locations in the first state for the tails of at least some of the identified wedge-vector pairs. The method then uses the wedge-vector pairs that have assigned tail locations to propagate the first cost function.