摘要

In this paper, a method for constructing rational function by weighted Lagrange interpolation of bivariate function over rectangular grid is discussed, and special form of formula on data points whose abscissas and ordinates are distinct respectively is also given. By this means, problem of branched continued fraction interpolation method (when inverse difference does not exist) can be solved, and on surface approximation and data fitting in three-dimensional space, by properly choosing different weight functions, we can obtain a variety of rational functions, and can reduce the order of the denominator, improve the precision of surface approximation.

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