In this paper, we construct a derivative-free multi-step iterative scheme based on Steffensen's method. To avoid excessively increasing the number of functional evaluations and, at the same time, to increase the order of convergence, we freeze the divided differences used from the second step and use a weight function on already evaluated operators. Therefore, we define a family of multi-step methods with convergence order 2m, where m is the number of steps, free of derivatives, with several parameters and with dynamic behaviour, in some cases, similar to Steffensen's method. In addition, we study how to increase the convergence order of the defined family by introducing memory in two different ways: using the usual divided differences and the Kurchatov divided differences. We perform some numerical experiments to see the behaviour of the proposed family and suggest different weight functions to visualize with dynamical planes in some cases the dynamical behaviour.
翻译:在本文中,我们根据Stef Defency的方法,构建了一个无衍生物的多阶段迭接机制。为了避免过度增加功能评价的数量,同时为了提高趋同的顺序,我们冻结了从第二步使用的不同差异,并对已经评估过的操作者使用加权函数。因此,我们定义了一个多步方法的组合,即2m级趋同,M是没有衍生物的阶梯数,M是没有衍生物的阶梯数,在某些情况下,有几个参数和动态行为,类似于Stef Defenn的方法。此外,我们研究如何通过两种不同的方式增加定义家庭的趋同顺序:使用通常的分歧和Kurchatov的分歧。我们进行了一些数字实验,以观察拟议家庭的行为,并提出不同重量功能,以便在某些情况下与动态平面视觉。