OBJECT-ORIENTED MATRIX CLASSES FOR USE IN A FINITE-ELEMENT CODE USINGC++

This paper presents a new method of writing finite element programs us ing the programming approach known as object oriented programming (OOP ). More Specifically, the C++ language is used to illustrate the key O OP concepts. In addition to the OOP finite element examples, a detaile d discussion of OOP techniques in the creation of a generalized matrix library is presented. The C++ language is used in this paper because it is more suited to numerical programs than a pure OOP language such as Smalltalk. The efficiency, flexibility and maintainability of the C ++ program are shown,to be superior to a comparable version written in anon-OOP language, such as FORTRAN. The matrix library contains a num ber of matrix objects that are useful for specific types of matrix rel ated problems. Different sparse storage schemes are implemented for ea ch different type of matrix. A large number of functions are provided for each matrix type in order to implement many common matrix operatio ns. In applications, the OOP paradigm allows the functions to be used in a very simple way that is common to all the matrix types. The sampl e finite element code included in this paper is primarily intended to illustrate the key concepts of OOP style. This paper explains how tb s et up a finite element hierarchy, material hierarchy and how to integr ate this with the matrix hierarchy (library). Thus, a completely objec t oriented finite element program can be written.