Abstract
Algorithms are presented for fitting a nonnegative Powell-Sabin spline to a set of scattered data. Existing necessary and sufficient nonnegativity conditions for a quadratic polynomial on a triangle are used to compose a set of necessary and sufficient nonnegativity constraints for the PS-spline. The PS-spline is expressed as a linear combination of locally supported basis functions, of which the Bernstein-Bézier representation is considered to improve the efficiency. Numerical examples illustrate the profit of nonnegative surface fitting with Powell-Sabin splines.
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Communicated by C. Brezinski
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Willemans, K., Dierckx, P. Nonnegative surface fitting with Powell-Sabin splines. Numer Algor 9, 263–276 (1995). https://doi.org/10.1007/BF02141591
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DOI: https://doi.org/10.1007/BF02141591