On Characterization of Poised Nodes for a Space of Bivariate Functions
- 1 Department of Informatics and Applied Mathematics, Yerevan State University, Yerevan, Armenia
- 2 Department of Informatics and Applied Mathematics, Yerevan State University, Yerevan, Armenia
Abstract
There are several examples of spaces of univariate functions for which we have a characterization of all sets of knots which are poised for the interpolation problem. For the standard spaces of univariate polynomials, or spline functions the mentioned results are well-known. In contrast with this, there are no such results in the bivariate case. As an exception, one may consider only the Pascal classic theorem, in the interpolation theory interpretation. In this paper, we consider a space of bivariate piecewise linear functions, for which we can readily find out whether the given node set is poised or not. The main tool we use for this purpose is the reduction by a basic subproblem, introduced in this paper.
- Bojanov, B.D., Hakopian, H. and Sahakian, A. (1993) Spline Functions and Multivariate Interpolations, Mathematics and Its Applications. Vol. 248, Kluwer Acad. Publishers Group, Dordrecht.
- Schoenberg, I.J. and Whitney, A. (1949) Sur la positivié des déterminants de translations des fonctions de fréquence de Pólya avec une application a une problèeme d’interpolation. C. R. Acad. Sci. Paris Ser. A, 228, 1996-1998.
- Schoenberg, I.J. and Whitney, A. (1953) On Pólya Frequency Functions. III. The Positivity of Translation Determinants with an Application to the Interpolation Problem by Spline curves. Transactions of the American Mathematical Society, 74, 246-259.
- Hakopian, H., Jetter, K. and Zimmermann, G. (2009) Vandermonde Matrices for Intersection Points of Curves. Jaen Journal on Approximation, 1, 67-81.