共查询到20条相似文献,搜索用时 78 毫秒
1.
Sergio Amat Sonia Busquier Antonio Escudero J. Carlos Trillo 《Journal of Computational and Applied Mathematics》2008
This note is devoted to Lagrange interpolation for continuous piecewise smooth functions. A new family of interpolatory functions with explicit approximation error bounds is obtained. We apply the theory to the classical Lagrange interpolation. 相似文献
2.
Ravi P. Agarwal Patricia J.Y. Wong 《Journal of Computational and Applied Mathematics》2010,234(8):2543-302
The purpose of this paper is to develop piecewise complementary Lidstone interpolation in one and two variables and establish explicit error bounds for the derivatives in L∞ and L2 norms. 相似文献
3.
Summary. Using a method based on quadratic nodal spline interpolation, we define a quadrature rule with respect to arbitrary nodes,
and which in the case of uniformly spaced nodes corresponds to the Gregory rule of order two, i.e. the Lacroix rule, which
is an important example of a trapezoidal rule with endpoint corrections. The resulting weights are explicitly calculated,
and Peano kernel techniques are then employed to establish error bounds in which the associated error constants are shown
to grow at most linearly with respect to the mesh ratio parameter. Specializing these error estimates to the case of uniform
nodes, we deduce non-optimal order error constants for the Lacroix rule, which are significantly smaller than those calculated
by cruder methods in previous work, and which are shown here to compare favourably with the corresponding error constants
for the Simpson rule.
Received July 27, 1998/ Revised version received February 22, 1999 / Published online January 27, 2000 相似文献
4.
R. CairaF. Dell’Accio F. Di Tommaso 《Journal of Computational and Applied Mathematics》2012,236(7):1691-1707
We propose a new combination of the bivariate Shepard operators (Coman and Trîmbi?a?, 2001 [2]) by the three point Lidstone polynomials introduced in Costabile and Dell’Accio (2005) [7]. The new combination inherits both degree of exactness and Lidstone interpolation conditions at each node, which characterize the interpolation polynomial. These new operators find application to the scattered data interpolation problem when supplementary second order derivative data are given (Kraaijpoel and van Leeuwen, 2010 [13]). Numerical comparison with other well known combinations is presented. 相似文献
5.
We construct local subdivision schemes that interpolate functional univariate data and that preserve convexity. The resulting
limit function of these schemes is continuous and convex for arbitrary convex data. Moreover this class of schemes is restricted
to a subdivision scheme that generates a limit function that is convex and continuously differentiable for strictly convex
data. The approximation order of this scheme is four. Some generalizations, such as tension control and piecewise convexity
preservation, are briefly discussed.
November 29, 1996. Date revised: May 28, 1997. 相似文献
6.
Shayne Waldron 《Numerische Mathematik》1998,80(3):461-494
Summary. The main result of this paper is an abstract version of the Kowalewski–Ciarlet–Wagschal
multipoint Taylor formula for representing the pointwise error in multivariate Lagrange interpolation. Several applications of this result are given
in the paper. The most important of these is the construction of a multipoint Taylor error formula for a general finite element, together with the corresponding –error bounds. Another application is the construction of a family of error formul? for linear interpolation (indexed by real
measures of unit mass) which includes some recently obtained formul?. It is also shown how the problem of constructing an
error formula for Lagrange interpolation from a D–invariant space of polynomials with the property that it involves only derivatives which annihilate the interpolating space
can be reduced to the problem of finding such a formula for a ‘simpler’ one–point interpolation map.
Received March 29, 1996 / Revised version received November 22, 1996 相似文献
7.
Lothar Reichel 《BIT Numerical Mathematics》1990,30(2):332-346
The Newton form is a convenient representation for interpolation polynomials. Its sensitivity to perturbations depends on the distribution and ordering of the interpolation points. The present paper bounds the growth of the condition number of the Newton form when the interpolation points are Leja points for fairly general compact sets K in the complex plane. Because the Leja points are defined recursively, they are attractive to use with the Newton form. If K is an interval, then the Leja points are distributed roughly like Chebyshev points. Our investigation of the Newton form defined by interpolation at Leja points suggests an ordering scheme for arbitrary interpolation points.Research supported in part by NSF under Grant DMS-8704196 and by U.S. Air Force Grant AFSOR-87-0102.On leave from University of Kentucky, Department of Mathematics, Lexington, KY 40506, U.S.A. 相似文献
8.
In convex interpolation the curvature of the interpolants should be as small as possible. We attack this problem by treating
interpolation subject to bounds on the curvature. In view of the concexity the lower bound is equal to zero while the upper
bound is assumed to be piecewise constant. The upper bounds are called fair with respect to a function class if the interpolation
problem becomes solvable for all data sets in strictly convex position. We derive fair a priori bounds for classes of quadraticC
1, cubicC
2, and quarticC
3 splines on refined grids. 相似文献
9.
This paper discusses various aspects of Hermite–Birkhoff interpolation that involve prescribed values of a function and/or its first derivative. An algorithm is given that finds the unique polynomial satisfying the given conditions if it exists. A mean value type error term is developed which illustrates the ill-conditioning present when trying to find a solution to a problem that is close to a problem that does not have a unique solution. The interpolants we consider and the associated error term may be useful in the development of continuous approximations for ordinary differential equations that allow asymptotically correct defect control. Expressions in the algorithm are also useful in determining whether certain specific types of problems have unique solutions. This is useful, for example, in strategies involving approximations to solutions of boundary value problems by collocation. 相似文献
10.
J. M. de Villiers 《Numerische Mathematik》1993,66(1):123-137
Summary The Gregory rule is a well-known example in numerical quadrature of a trapezoidal rule with endpoint corrections of a given order. In the literature, the methods of constructing the Gregory rule have, in contrast to Newton-Cotes quadrature,not been based on the integration of an interpolant. In this paper, after first characterizing an even-order Gregory interpolant by means of a generalized Lagrange interpolation operator, we proceed to explicitly construct such an interpolant by employing results from nodal spline interpolation, as established in recent work by the author and C.H. Rohwer. Nonoptimal order error estimates for the Gregory rule of even order are then easily obtained. 相似文献
11.
Solveig Bruvoll 《Journal of Computational and Applied Mathematics》2010,233(7):1631-1639
Mean value interpolation is a simple, fast, linearly precise method of smoothly interpolating a function given on the boundary of a domain. For planar domains, several properties of the interpolant were established in a recent paper by Dyken and the second author, including: sufficient conditions on the boundary to guarantee interpolation for continuous data; a formula for the normal derivative at the boundary; and the construction of a Hermite interpolant when normal derivative data is also available. In this paper we generalize these results to domains in arbitrary dimension. 相似文献
12.
On vector subdivision 总被引:8,自引:0,他引:8
In this paper we give a complete characterization of the convergence of stationary vector subdivision schemes and the regularity
of the associated limit function. These results extend and complete our earlier work on vector subdivision and its use in
the construction of multiwavelets.
Received March 19, 1997; in final form November 13, 1997 相似文献
13.
Multivariate Birkhoff interpolation is the most complex polynomial interpolation problem and people know little about it so far. In this paper, we introduce a special new type of multivariate Birkhoff interpolation and present a Newton paradigm for it. Using the algorithms proposed in this paper, we can construct a Hermite system for any interpolation problem of this type and then obtain a Newton basis for the problem w.r.t. the Hermite system. 相似文献
14.
Joris Van Deun 《Journal of Computational and Applied Mathematics》2010,235(4):1077-1084
We study rational interpolation formulas on the interval [−1,1] for a given set of real or complex conjugate poles outside this interval. Interpolation points which are near-best in a Chebyshev sense were derived in earlier work. The present paper discusses several computation aspects of the interpolation points and the corresponding interpolants. We also study a related set of points (that includes the end points), which is more suitable for applications in rational spectral methods. Some examples are given at the end of this paper. 相似文献
15.
In this paper, we describe a recursive method for computing interpolants defined in a space spanned by a finite number of continuous functions in Rd. We apply this method to construct several interpolants such as spline interpolants, tensor product interpolants and multivariate polynomial interpolants. We also give a simple algorithm for solving a multivariate polynomial interpolation problem and constructing the minimal interpolation space for a given finite set of interpolation points. 相似文献
16.
It is well known that rational interpolation sometimes gives better approximations than polynomial interpolation, especially
for large sequences of points, but it is difficult to control the occurrence of poles. In this paper we propose and study
a family of barycentric rational interpolants that have no real poles and arbitrarily high approximation orders on any real
interval, regardless of the distribution of the points. These interpolants depend linearly on the data and include a construction
of Berrut as a special case. 相似文献
17.
This is the second part of a note on interpolation by real polynomials of several real variables. For certain regular knot systems (geometric or regular meshes, tensor product grids), Neville-Aitken algorithms are derived explicitly. By application of a projectivity they can be extended in a simple way to arbitrary (k+1)-pencil lattices as recently introduced by Lee and Phillips. A numerical example is given.Partially supported by CICYT Res. Grant PS87-0060.Travel Grant Programa Europa 1991, CAI Zaragoza. 相似文献
18.
Remarks on a unified theory for classical and generalized interpolation and extrapolation 总被引:1,自引:0,他引:1
Tore Håvie 《BIT Numerical Mathematics》1981,21(4):465-474
A unified theory for generalized interpolation, as developed by Mühlbach, and classical polynomial interpolation is discussed. A fundamental theorem for generalized linear iterative interpolation is given and used to derive generalizations of the classical formulae due to Neville, Aitken and Lagrange. Using Mühlbach's definition of generalized divided differences, Newton's generalized interpolation formula, including an expression for the error term, is derived as a pure identity. 相似文献
19.
Quasi-interpolation of radial basis functions on finite grids is a very useful strategy in approximation theory and its applications. A notable strongpoint of the strategy is to obtain directly the approximants without the need to solve any linear system of equations. For radial basis functions with Gaussian kernel, there have been more studies on the interpolation and quasi-interpolation on infinite grids. This paper investigates the approximation by quasi-interpolation operators with Gaussian kernel on the compact interval. The approximation errors for two classes of function with compact support sets are estimated. Furthermore, the approximation errors of derivatives of the approximants to the corresponding derivatives of the approximated functions are estimated. Finally, the numerical experiments are presented to confirm the accuracy of the approximations. 相似文献
20.
Summary. A posteriori error estimators of residual type are derived for piecewise linear finite element approximations to elliptic
obstacle problems. An instrumental ingredient is a new interpolation operator which requires minimal regularity, exhibits
optimal approximation properties and preserves positivity. Both upper and lower bounds are proved and their optimality is
explored with several examples. Sharp a priori bounds for the a posteriori estimators are given, and extensions of the results
to double obstacle problems are briefly discussed.
Received June 19, 1998 / Published online December 6, 1999 相似文献