English

An algebraic characterization of B-splines

Classical Analysis and ODEs 2021-12-08 v1

Abstract

B-splines of order kk can be viewed as a mapping NN taking a (k+1)(k+1)-tuple of increasing real numbers a0<<aka_0 < \cdots < a_k and giving as a result a certain piecewise polynomial function. Looking at this mapping NN as a whole, basic roperties of B-spline functions imply that it has the following algebraic properties: (1) N(a0,,ak)N(a_0,\ldots,a_k) has local support; (2) N(a0,,ak)N(a_0,\ldots,a_k) allows refinement, i.e. for every aj=0k1(aj,aj+1)a\in \cup_{j=0}^{k-1} (a_j,a_{j+1}) we have that if (α0,,αk+1)(\alpha_0,\ldots, \alpha_{k+1}) is the increasing rearrangement of the points {a0,,ak,a}\{a_0,\ldots,a_k,a\}, the 'old' function N(a0,,ak)N(a_0,\ldots,a_k) is a linear combination of the 'new' functions N(α0,,αk)N(\alpha_0,\ldots,\alpha_k) and N(α1,,αk+1)N(\alpha_1,\ldots,\alpha_{k+1}); (3) NN is translation and dilation invariant. It is easy to see that derivatives of N(a0,,ak)N(a_0,\ldots,a_k) satisfy properties (1)-(3) as well. In this paper we investigate if properties (1)-(3) are already sufficient to characterize B-splines and their derivatives.

Keywords

Cite

@article{arxiv.2112.03664,
  title  = {An algebraic characterization of B-splines},
  author = {Anna Kamont and Markus Passenbrunner},
  journal= {arXiv preprint arXiv:2112.03664},
  year   = {2021}
}
R2 v1 2026-06-24T08:07:29.524Z