Based on the Sinc approximation combined with the tanh transformation, Haber derived an approximation formula for numerical indefinite integration over the finite interval (-1, 1). The formula, (SE1) uses a special function for the basis functions. In contrast, Stenger derived another formula (SE2), which does not use any special function but does include a double sum. Subsequently, Muhammad and Mori proposed the formula (DE1), which replaces the tanh transformation with the double-exponential transformation in the formula (SE1). Almost simultaneously, Tanaka et al. proposed the formula (DE2), which was based on the same replacement in (SE2). As they reported, the replacement drastically improves the convergence rate of (SE1) and (SE2). In addition to the formulas above, Stenger derived yet another indefinite integration formula (SE3) based on the Sinc approximation combined with the tanh transformation, which has an elegant matrix-vector form. In this paper, we propose the replacement of the tanh transformation with the double-exponential transformation in the formula (SE3). We provide a theoretical analysis as well as a numerical comparison.
翻译:根据Sinc近似值加上Tanh变异,Haber得出了一个在有限间隔(-1,1)内进行数字无限期合并的近似公式(SE1),公式(SE1)对基础函数使用一种特殊函数。相反,Senger得出另一种公式(SE2),该公式不使用任何特殊函数,但确实包含一个双重总和。随后,Muhammad和Mori提出了公式(DE1),该公式用公式(SE1)中的双重利用变异(SE1)取代Tanh变异(DE2)。Tana等人几乎同时提出了公式(DE2),该公式以(SE2)中的同一替换为基础。正如他们所报告的那样,该替换大大提高了(SE1)和(SE2)的合并率。除上述公式外,Stenger还根据Sinc 近似值和Tranh变异形(SE3)得出了另一种不定期合并公式(SE3),该公式具有一种优雅的矩阵-矢量表。在本文件中,我们提议用公式(SE3)的双重变异变变换,我们提供理论分析和数字比较。我们提供理论分析和数字比较。