The reconstruction approach [Shu C.W.: {\em SIAM Rev.} {\bf 51} (2009) 82--126] for the numerical approximation of $f'(x)$ is based on the construction of a dual function $h(x)$ whose sliding averages over the interval $[x-\tfrac{1}{2}Δx,x+\tfrac{1}{2}Δx]$ are equal to $f(x)$ (assuming an homogeneous grid of cell-size $Δx$). We study the deconvolution problem [Harten A., Engquist B., Osher S., Chakravarthy S.R.: {\em J. Comp. Phys.} {\bf 71} (1987) 231--303] which relates the Taylor polynomials of $h(x)$ and $f(x)$, and obtain its explicit solution, by introducing rational numbers $τ_n$ defined by a recurrence relation, or determined by their generating function, $g_τ(x)$, related with the reconstruction pair of ${\rm e}^x$. We then apply these results to the specific case of Lagrange-interpolation-based polynomial reconstruction, and determine explicitly the approximation error of the Lagrange reconstructing polynomial (whose sliding averages are equal to the Lagrange interpolating polynomial) on an arbitrary stencil defined on a homogeneous grid.
Lagrange interpolation processes based on the zeros of anti-Gauss Jacobi polynomials
University of Cagliari(卡利亚里大学);Insubria University(因斯布鲁克大学);University of Basilicata(巴西利卡塔大学);Istituto per le Applicazioni del Calcolo “Mauro Picone”, Naples branch, C.N.R. National Research Council of Italy(意大利国家研究委员会计算应用研究所“毛罗·皮切内”那不勒斯分部)
Reconstructing sparse exponential polynomials from samples: Stirling numbers and Hermite interpolation
Lehrstuhl für Mathematik mit Schwerpunkt Digitale Bildverarbeitung & FORWISS, University of Passau(帕绍大学数字图像处理重点数学研究所与FORWISS);University of Passau(帕绍大学)
Lagrange interpolation at real projections of Leja sequences for the unit disk
Université Paul Sabatier(图卢兹第三大学);Institut de Mathématiques, Université de Toulouse III and CNRS (UMR 5219)(图卢兹第三大学数学研究所及法国国家科学研究中心);Hanoi University of Education(河内师范大学)
On the filtered polynomial interpolation at Chebyshev nodes
本文讨论了一种特殊的滤波逼近方法,它利用de la Vallée Poussin滤波器在Chebyshev零点处产生插值多项式。这些多项式可以是一个有用的设备,许多理论和应用问题,因为它们结合了经典的拉格朗日插值的优点,在空间的局部连续函数配备适当的,Jacobi-加权,统一规范的一致收敛性收敛。相关的勒贝格常数的一致有界性,即Lagrange插值所缺少的一致收敛性,已经在文献中在不同的但仅仅是充分的假设下得到了证明.在这里,我们陈述了得到它的充要条件,这些条件很容易检验,因为它们是关于定义范数的Jacobi权的指数的简单不等式。此外,他们是必要的和足够的,以获得一个接近最佳逼近误差的过滤插值多项式,它趋于零的节点数$n$趋于无穷大。此外,收敛速度与$n$次最佳多项式逼近的误差相当,因此逼近阶随着所寻求函数的光滑性而提高。给出了几个数值实验,以检验理论结果,在相同的节点上与拉格朗日插值进行比较,并显示如何可以大大减少吉布斯现象。
Structure-preserving upwind Lagrange multiplier schemes for solid-state dewetting with a logarithmic Flory--Huggins potential
School of Mathematics and Statistics, Henan University(河南大学数学与统计学院);Center for Applied Mathematics of Henan Province, Henan University(河南省应用数学中心);School of Artificial Intelligence, Wuhan University(武汉大学人工智能学院)
A Multi-step Scheme based on Cubic Spline for solving Backward Stochastic Differential Equations
Lehrstuhl für Angewandte Mathematik und Numerische Analysis, Fakultät für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal(伍珀塔尔大学数学与自然科学学院应用数学与数值分析讲席)
Some remarks on filtered polynomial interpolation at Chebyshev nodes
本文研究了四类Chebyshev节点上的滤波de la Vallée Poussin(VP)插值。这种近似模型是有趣的应用,因为它结合了经典的拉格朗日多项式逼近(插值和多项式保持)与过滤近似(一致有界的勒贝格常数和减少的吉布斯现象)的优点。在这里,我们重点介绍一些在滤波VP插值应用中有用的附加功能。特别地,我们分析了VP插值多项式的导数所提供的同时逼近。此外,我们还证明了VP逼近算子在Sobolev和Hölder-Zygmund空间中的一致有界性,其中几个积分-微分模型是唯一稳定可解的.