Theoretical study of subregion method and its applications

The theoretical foundation of the subregion method for solving electrostatic and magnetostatic field problems is discussed, and several kinds of subregion methods, including the common combination method, are described. They can be used to solve nonlinear as well as linear field problems. The diakoptical technique is developed and implemented to make the subregion method more effective. Examples are given, showing that (1) more accurate calculations can be made; (2) larger, more complicated problems can be calculated owing to the relatively smaller size of the matrix; (3) the computation time is reduced, especially for nonlinear fields