两类求解y″＝f（x，y）具有极小相位延迟的显式方法

TWO FAMILIES OF EXPLICIT METHODS WITH MINIMAL PHASE-LAG FOR y"=f(x,y)

本文提出了两类数值积分二阶周期性初值问题ｙ″＝ｆ（ｘ，ｙ），ｙ（ｘ０）＝ｙ０，ｙ＇（ｘ０）＝ｙ＇０具有极小相位延迟的显式两步法。这些方法推广和改进了文献［１］－［７］中的某些方法。数值试验表明本文中的某些方法优于［１］－［７］中的某些方法。

In this paper, two families of explicit two-step methods with minimal phase-lag for the numerical integration of second order periodic initial-value problems are suggested.These methods have the advantage of higher accuracy, considerably small phase-lag and larger interval of periodicity than the explicit methods in [1]-[7]. Numerical experiments show that these methods presented in this paper are efficient.