DASP3: A Program for the Numerical Integration of Partitioned Stiff Ordinary Differential Equations and Differential Algebraic Systems

摘要

The DASP3 program is a fixed order, variable step FORTRAN code for the numerical integration of partitioned systems of stiff differential equations and differential algebraic equations. Given a differential system, some equations may be specified to be stiff and others to be nonstiff. Nonstiff equations are then integrated by the classic fourth order Runge-Kutta method while the third order backward differentiation method is used for the stiff part of the system. In this way a system with only few equations causing stiffness can be treated more efficiently than with a standard code for stiff problems implementing a fully implicit method. Numerical aspects as well as the implementation and usage of the method are discussed. A source code listing of DASP3 and its auxiliary routines is also presented.