文摘
Explicit Runge-Kutta methods can efficiently be used in the numerical integration of initial value problems for non-stiff systems of ordinary differential equations (ODEs). Let m and p be the number of stages and the order of a given explicit Runge-Kutta method. We have proved in a previous paper [8] that the combination of any explicit Runge-Kutta method with \(m=p\) and the Richardson Extrapolation leads always to a considerable improvement of the absolute stability properties. We have shown in [7] (talk presented at the NM&A14 conference in Borovets, Bulgaria, August 2014) that the absolute stability regions can be further increased when \(p<m\) is assumed. For two particular cases, \(p=3 \wedge m=4\) and \(p=4 \wedge m=6\) it is demonstrated that(a) the absolute stability regions of the new methods are larger than those of the corresponding explicit Runge-Kutta methods with \(p=m\), and