SystemBase

The SystemBase is an abstract class that represents a system of equations. It is the basis for the NonlinearSystem, AuxiliarySystem, and DisplacedSystem objects. Each System contains the necessary objects for holding a mesh, one or more field variables (discretized on that mesh) and one or more scalar variables (DOFs not directly associated with the mesh). Access to raw numeric vectors, which contain solution information all go through this class and its derived objects.