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Fractal-classic interpolants

M. A. Navascués, M. V. Sebastián (2009)

Banach Center Publications

The methodology of fractal interpolation is very useful for processing experimental signals in order to extract their characteristics of complexity. We go further and prove that the Iterated Function System involved may also be used to obtain new approximants that are close to classical ones. In this work a classical function and a fractal function are combined to construct a new interpolant. The fractal function is first defined as a perturbation of a classical mapping. The additional condition...

Further convergence results for two quadrature rules for Cauchy type principal value integrals

Nikolaos I. Ioakimidis (1982)

Aplikace matematiky

New convergence and rate-of-convergence results are established for two well-known quadrature rules for the numerical evaluation of Cauchy type principal value integrals along a finite interval, namely the Gauss quadrature rule and a similar interpolatory quadrature rule where the same nodes as in the Gauss rule are used. The main result concerns the convergence of the interpolatory rule for functions satisfying the Hölder condition with exponent less or equal to 1 2 . The results obtained here supplement...

Geodesic metrics for RBF approximation of some physical quantities measured on sphere

Karel Segeth (2024)

Applications of Mathematics

The radial basis function (RBF) approximation is a rapidly developing field of mathematics. In the paper, we are concerned with the measurement of scalar physical quantities at nodes on sphere in the 3D Euclidean space and the spherical RBF interpolation of the data acquired. We employ a multiquadric as the radial basis function and the corresponding trend is a polynomial of degree 2 considered in Cartesian coordinates. Attention is paid to geodesic metrics that define the distance of two points...

Harmonic interpolation based on Radon projections along the sides of regular polygons

Irina Georgieva, Clemens Hofreither, Christoph Koutschan, Veronika Pillwein, Thotsaporn Thanatipanonda (2013)

Open Mathematics

Given information about a harmonic function in two variables, consisting of a finite number of values of its Radon projections, i.e., integrals along some chords of the unit circle, we study the problem of interpolating these data by a harmonic polynomial. With the help of symbolic summation techniques we show that this interpolation problem has a unique solution in the case when the chords form a regular polygon. Numerical experiments for this and more general cases are presented.

Hermite interpolation: a survey of univariate computational methods.

G. Mühlbach (2002)

RACSAM

Se considera la interpolación de Hermite de funciones de una variable mediante polinomios generalizados. Se pretende mostrar que técnicas computacionales conocidas para interpolación polinómica se pueden aplicar también a interpolación mediante polinomios generalizados. Como aplicación se estudia con cierto detalle la interpolación mediante funciones racionales con polos prefijados. La interpolación polinómica corresponde al caso particular en que todos los polos prefijados están en el infinito.

Image Interpolation

Vicent Caselles, Simon Masnou, Jean-Michel Morel, Catalina Sbert (1997/1998)

Séminaire Équations aux dérivées partielles

We discuss possible algorithms for interpolating data given in a set of curves and/or points in the plane. We propose a set of basic assumptions to be satisfied by the interpolation algorithms which lead to a set of models in terms of possibly degenerate elliptic partial differential equations. The Absolute Minimal Lipschitz Extension model (AMLE) is singled out and studied in more detail. We show experiments suggesting a possible application, the restoration of images with poor dynamic range. We...

Interpolating and smoothing biquadratic spline

Radek Kučera (1995)

Applications of Mathematics

The paper deals with the biquadratic splines and their use for the interpolation in two variables on the rectangular mesh. The possibilities are shown how to interpolate function values, values of the partial derivative or values of the mixed derivative. Further, the so-called smoothing biquadratic splines are defined and the algorithms for their computation are described. All of these biquadratic splines are derived by means of the tensor product of the linear spaces of the quadratic splines and...

Interpolation formulas for functions of exponential type

Josef Kofroň, Emílie Moravcová (2001)

Applications of Mathematics

In the paper we present a derivative-free estimate of the remainder of an arbitrary interpolation rule on the class of entire functions which, moreover, belong to the space L ( - , + ) 2 . The theory is based on the use of the Paley-Wiener theorem. The essential advantage of this method is the fact that the estimate of the remainder is formed by a product of two terms. The first term depends on the rule only while the second depends on the interpolated function only. The obtained estimate of the remainder of...

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