On Shifted Cardinal Interpolation by Gaussians and Multiquadrics
On Shifted Cardinal Interpolation by Gaussians and Multiquadrics
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关于高斯和多重二次曲面的平移基数插值
DOI:
10.1006/jath.1996.0091
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发表时间:
1996
影响因子:
0.9
通讯作者:
N. Sivakumar
中科院分区:
文献类型:
--
作者:
B. Baxter;N. Sivakumar
A radial basis function approximation is a linear combination of translates of a fixed function�:�Rd�R. Such functions possess many useful and interesting properties when the translates are integers and�is radially symmetric. We study the closely related problem for which the fixed function is the shifted Gaussian�=G(���), whereG(x)=exp(���x�22) and��Rd. Specifically, we exploit the theory of elliptic functions to establish the invertibility of the Toeplitz operatorformula]when�has no half-integer components; it is singular otherwise. This implies the existence of ashifted Gaussian cardinal function, that is, a linear combination�of integer translates of the shifted Gaussian satisfying�(j)=�0j. We also study shifted cardinal functions when the parameter�tends to zero. In particular, we discover their uniform convergence to the sinc function when the shift vector�possesses no half-integer components. Our methods are based in part on similar results established by the first author when the basis function is the Hardy multiquadric. Several intriguing links with the theory of shifted B-spline cardinal interpolation are described in the finale.