In this paper, we study a geometric G^2 Hermite interpolation by planar rational cubic Bézier curves. Two data points, two tangent vectors and two signed curvatures interpolated per each rational segment. We give the necessary and the sufficient intrinsic geometric conditions for two C^2 parametric curves to be connected with G2 continuity. Locally, the free parameters w...

In this paper we present a novel interpolation technique for Vlasov simulations of intense space charge dominated beams. This new technique enables to localize the cubic spline interpolation generally performed in semi-Lagrangian Vlasov codes and thus to improve the scalability of the parallel version. This new method is applied to the propagation of a potassium beam in a periodic focusing chan...

Cumulative chord C piecewise-cubics, for unparameterized data from regular curves in R , are constructed as follows. In the first step derivatives at given ordered interpolation points are estimated from ordinary (non-C) cumulative chord piecewise-cubics. Then Hermite interpolation is used to generate a C piecewise-cubic interpolant. Theoretical estimates of orders of approximation are establis...

Transfinite mean value interpolation has recently emerged as a simple and robust way to interpolate a function f defined on the boundary of a planar domain. In this paper we study basic properties of the interpolant, including sufficient conditions on the boundary of the domain to guarantee interpolation when f is continuous. Then, by deriving the normal derivative of the interpolant and of a m...

We consider the problem of computing univariate polynomial matrices over a field that represent minimal solution bases for a general interpolation problem, some forms of which are the vector M-Padé approximation problem in [Van Barel and Bultheel, Numerical Algorithms 3, 1992] and the rational interpolation problem in [Beckermann and Labahn, SIAM J. Matrix Anal. Appl. 22, 2000]. Particular inst...

The Euclidean Algorithm is the often forgotten key to rational approximation techniques, including Taylor, Lagrange, Hermite, osculating, cubic spline, Chebyshev, Padé and other interpolation schemes. A unified view of these various interpolation techniques is eloquently expressed in terms of the concept of the spectral basis of a factor ring of polynomials. When these methods are applied to th...

In this paper a G2 continuous geometric interpolation of Hermite data by Pythagoreanhodograph (PH) quintic curves in Rd is considered. For two sets of appropriate Hermite data (tangent directions and curvature vectors) at two distinct points a PH quintic which interpolates given data geometrically is sought. The problem reduces to solving a system of nonlinear algebraic equations involving only...

Let Q : R-R be even, nonnegative and continuous, Q0 be continuous, Q040 in ð0;NÞ; and let Q00 be continuous in ð0;NÞ: Furthermore, Q satisfies further conditions. We consider a certain generalized Freud-type weight W 2 rQðxÞ 1⁄4 jxj 2r expð 2QðxÞÞ: In previous paper (J. Approx. Theory 121 (2003) 13) we studied the properties of orthonormal polynomials fPnðW 2 rQ; xÞg N n1⁄40 with the generalize...

In applications it is useful to compute the local average of a function f(u) of an input u from empirical statistics on u. A very simple relation exists when the local averages are given by a Haar approximation. The question is to know if it holds for higher order approximation methods. To do so, it is necessary to use approximate product operators defined over linear approximation spaces. Thes...