Thus, if is a nonlinear operator and is a vector in the domain, then the evaluation object represents the triple The purpose of having an evaluation object is to deal with the common situation in which the operator image and derivatives share some intermediate calculations. A typical implementation of such an operator involves defining an evaluation object whose constructor performs these intermediate calculations. The Image method then completes the computation of the operator image, while the PartialDeriv and SecondPartialDeriv methods complete the calculation of the derivatives. The ImageRef method invokes Image to get the image and returns a reference to it. On subsequent calls, ImageRef merely references the stored value.
Range Returns a reference to the range of the underlying operator.
Image Computes the image of the operator at the point at which this object was created. Must be implemented by the creator of a concrete class. ImageRef Calls Image , if necessary, to compute the operator image, saves it, and returns it. Implemented in the base class. Must be implemented by the creator of a concrete class.