On integro quartic spline interpolation

In this paper, we use quartic B-spline to construct an approximating function to agree with the given integral values of a univariate real-valued function over the same intervals. It is called integro quartic spline interpolation. Our interpolation method is new and easy to implement. Moreover, it can work successfully even without any boundary conditions. The interpolation errors are studied. The super convergence (sixth order and fourth order, respectively) in approximating function values and second-order derivative values at the knots is proved. Numerical examples illustrate that our method is very effective and our integro-interpolating quartic spline has higher approximation ability than others.     

The possibility of periodic spline interpolation

A new case of the solvability of the classical interpolation problem for periodic splines is described.Translated from Matematicheskie Zametki, Vol. 8, No. 5, pp. 563–573, November, 1970.I wish to thank S. B. Stechkin for his valuable suggestions and constant interest in this work.     

Optimal shift parameters for periodic spline interpolation

Using the exponential Euler spline, restricted on the unit circle, we sketch a unified approach to the periodic spline interpolation with shifted interpolation nodes. Mainly we are interested in the optimal choice of the shift parameter such that the corresponding interpolatory matrix possesses minimal condition or such that the related interpolation operator has minimal norm. We show that =0 is optimal in both cases. This improves known results of Merz, Reimer-Siepmann and Richards.     

Hermite spline interpolation in the discrete periodic case

Interpolation of discrete periodic complex-valued functions by the values and increments given at equidistant nodes is examined. A space of discrete functions in which the interpolation problem is uniquely solvable is introduced. Extremal and limit properties of the solution to this problem are found.     

Error bounds for anisotropic RBF interpolation

We present error bounds for the interpolation with anisotropically transformed radial basis functions for both a function and its partial derivatives. The bounds rely on a growth function and do not contain unknown constants. For polyharmonic basic functions in ${\mathbb{R}}^2$, we show that the anisotropic estimates predict a significant improvement of the approximation error if both the target function and the placement of the centers are anisotropic, and this improvement is confirmed numerically.     

On band circulant matrices in the periodic spline interpolation theory

We review and extend the analysis of band circulant matrices which occur in the periodic spline interpolation theory with equispaced knots. Explicit bounds on the inverse matrices are given.     

Error control process in function interpolation using statistical spline model

In this paper, we propose an algebraic method based on solving some inequalities of polynomial type to control the error value of interpolation formulas whose residue depends on a monic polynomial. This method then leads to construct some piecewise approximations (splines) of statistical type, which are based on a specific partition of the main interval. In other words, in this model of spline, approximate criteria are considered fixed and sub-intervals corresponding to criteria are derived as accurately as possible. In this sense, some statistical concepts such as expected value, variance measure, skewness and kurtosis coefficients are also inserted into the definition of statistical splines. Finally, a numerical results section is separately given to confirm all results in the paper.     

Quadratic spline interpolation with coinciding interpolation and spline grids

In this paper the quadratic spline interpolation with coinciding interpolation and spline grids for continuous functions is considered. The theorems mainly concern error estimations which allow to formulate a convergence statement. To get such results it is assumed that the function to be interpolated is suitably smooth or possesses a special behavior. A best approximation property and a statement about the solution of boundary value problems using quadratic spline functions are added.     

An efficient algorithm for periodic Hermite spline interpolation with shifted nodes

Generalized Hermite spline interpolation with periodic splines of defect 2 on an equidistant lattice is considered. Then the classic periodic Hermite spline interpolation with shifted interpolation nodes is obtained as a special case.By means of a new generalization of Euler-Frobenius polynomials the symbol of the considered interpolation problem is defined. Using this symbol, a simple representation of the fundamental splines can be given. Furthermore, an efficient algorithm for the computation of the Hermite spline interpolant is obtained, which is mainly based on the fast Fourier transform.     

Lebesgue constants for periodic Hermite spline interpolation operators on uniform lattices

We derive a complex line integral representation for the ebyshev norm of periodic spline interpolation operators of odd degree on uniform lattices. Several generalizations are indicated.     

Error estimate and extrapolation of a quadrature formula derived from a quartic spline quasi-interpolant

In this paper we analyze a quadrature rule based on integrating a C ³ quartic spline quasi-interpolant on a bounded interval which has been introduced in Sablonnière (Rend. Semin. Mat. Univ. Pol. Torino 63(3):107–118, 2005). By studying the sign structure of its associated Peano kernel we derive an explicit formula of the quadrature error with an approximation order O(h ⁶). A comparison of this rule with the composite Boole’s and the three-point Gauss-Legendre rules is given. We also compare the Nyström methods associated with the above quadrature formulae for solving the linear Fredholm integral equation of the second kind. Then, by combining the proposed rule with composite Boole’s rule, we construct a new quadrature rule of order O(h ⁷). All the obtained results are illustrated by several numerical tests.     

Best bounds on the distance between 3-direction quartic box spline surface and its control net

We present the best bounds on the distance between 3-direction quartic box spline surface patch and its control net by means of analysis and computing for the basis functions of 3-direction quartic box spline surface. Both the local bounds and the global bounds are given by the maximum norm of the first differences or second differences or mixed differences of the control points of the surface patch.     

Error estimates for discrete spline interpolation: Quintic and biquintic splines

In this paper we shall develop a class of discrete spline interpolates in one and two independent variables. Further, explicit error bounds in _?∞${?}_{\infty }$ norm are derived for the quintic and biquintic discrete spline interpolates. We also present some numerical examples to illustrate the results obtained.     

Error bounds for a convexity-preserving interpolation and its limit function

Error bounds between a nonlinear interpolation and the limit function of its associated subdivision scheme are estimated. The bounds can be evaluated without recursive subdivision. We show that this interpolation is convexity preserving, as its associated subdivision scheme. Finally, some numerical experiments are presented.     

Bivariate quartic spline spaces and quasi-interpolation operators

In this paper, we study two bivariate quartic spline spaces and , and present two classes of quasi-interpolation operators in the two spaces, respectively. Some results on the operators are given.