Method and apparatus for specifying a cost function that represents the estimated distance between an external state and a set of states in a space

摘要

Some embodiments of the invention provide a method of specifying a cost function that represents the estimated distance between an external state and a set of states in a multi-state space that represents a region of a design layout. The method identifies a first polygon that encloses the set of states. It then identifies vectors to project from the vertices of the first polygon. Based on the projected vectors, the method specifies a first cost function. The method also identifies a second polygon that encloses the set of states. It also identifies vectors to project from the vertices of the second polygon. Based on the projected vectors, the method specifies a second cost function. The method then derives a third cost function from the specified cost functions.