A Family of Nested General Linear Methods for Solving Ordinary Differential Equations
Peter O. Olatunji *
Department of Mathematical Sciences, Adekunle Ajasin University, P.M.B-001, Akungba, Akoko, Ondo State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
General linear methods (GLMs) was introduced as a generalization of Runge{Kutta methods (RKMs) and linear multistep methods (LMMs). The discovery of general linear method gave insight into the discovery of new methods that are neither RKMs or LMMs. Here, new classes of GLMs that are nested in their stages and mono-implicit in the output are presented, these methods are referred to as nested general linear methods (NGLMs). Procedures for deriving members that are algebraically stable are discussed herein and algebraically stable NGLMs have been derived up to order p = 5. Implementation procedure of these nested general linear methods which include the solution of non-linear systems of equations by simplified Newton iterations and step size changing strategy are discussed. The order p = 3 NGLM has been implemented on two test problems by variable step size, and the results compared with the results of MATLAB ode15s and RADAU IIA.
Keywords: General linear methods, nested GLMs, algebraic stability, G-matrix, order