This paper describes the problem of shape preserving approximation for data with speci ed tolerances Using the tool of generalized B splines GB splines for short simple one and three point algorithms of shape preserving local approximation with automatic choice of the tension parameters are de veloped In the two dimensional case tensor products of one dimensional splines are employed The result...

Easy to construct and optimally convergent generalisations of B-splines unstructured meshes are essential for the application isogeometric analysis domains with non-trivial topologies. Nonetheless, especially hexahedral meshes, construction smooth basis functions is still an open question. We introduce a simple partition unity that yields blended B-splines, referred as SB-splines, on semi-struc...

There are thousands of articles published on variants of splines, including least squares cubic splines. One of the first least squares articles was de Boor and Rice [1], and a comprehensive explanatory textbook is Dierckx [2]. Unfortunately, every example in the literature and on the web of a least squares cubic spline makes use of B-splines. While B-splines have a certain elegance, they are s...

A-splines are implicit real algebraic curves in Bernstein-B ezier (BB) form that are smooth. We develop a spectrum of physical A-spline curve models using various energy formulations based on the theory of elasticity. Our bending and stretching energy formulations yield interactive physically based modeling with A-splines while preserving the advantages of free-form modeling of complex shapes. ...

We give some empirical comparisons between two nonparametric regression methods based on regularization: the elastic or thin-plate splines, and plastic splines based on total variation penalties. 1. Nonparametric regression with elastic and plastic splines We seek f to fit the dependence of response points zi ∈ R on two-dimensional covariates (xi, yi) living in the domain Ω. To this end, we emp...

The convergences of three L1 spline methods for scattered data interpolation and fitting using bivariate spline spaces are studied in this paper. That is, L1 interpolatory splines, splines of least absolute deviation, andL1 smoothing splines are shown to converge to the given data function under some conditions and hence, the surfaces from these three methods will resemble the given data values...

Splines can be constructed by convolving the indicator function of a cell whose shifts tessellate Rn. This paper presents simple, geometric criteria that imply that, for regular shift-invariant tessellations, only a small subset of such spline families yield nested spaces: primarily the well-known tensor-product and box splines. Among the many nonrefinable constructions are hex-splines and thei...

In this paper we prove that there exists a unique positive symmetrical univariate B-spline with minimal support. It is obtained as linear combination of a minimal number of successive classical B-splines with multiple knots in the space, S d , of cardinal polynomial splines of class C and degree d. Next, we show that the approximation order in the space generated by the integer translates of th...