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In polynomial interpolation of two variables, the Padua points are the first known example (and up to now the only one) of a unisolvent point set (that is, the interpolating polynomial is unique) with ''minimal growth'' of their Lebesgue constant, proven to be O(log2 ''n'') .〔 〕 Their name is due to the University of Padua, where they were originally discovered.〔 〕 The points are defined in the domain . It is possible to use the points with four orientations, obtained with subsequent 90-degree rotations: this way we get four different families of Padua points. == The four families == We can see the Padua point as a "sampling" of a parametric curve, called ''generating curve'', which is slightly different for each of the four families, so that the points for interpolation degree and family can be defined as : Actually, the Padua points lie exactly on the self-intersections of the curve, and on the intersections of the curve with the boundaries of the square . The cardinality of the set is . Moreover, for each family of Padua points, two points lie on consecutive vertices of the square , points lie on the edges of the square, and the remaining points lie on the self-intersections of the generating curve inside the square.〔 〕〔 〕 The four generating curves are ''closed'' parametric curves in the interval , and are a special case of Lissajous curves. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Padua points」の詳細全文を読む スポンサード リンク
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