利用带参数的仅以被插函数的函数值作为插值条件的一元有理插值方法,构造了一种分母为双二次的仅基于函数值的二元有理双三次插值函数,插值函数具有简洁的显示表示.插值函数中含有四个参数,当这些参数满足一定条件时,插值曲面在插值区域上伊光滑.由于插值函数中含有参数,这样可以在插值数据不变的情况下通过对参数的选择进行插值曲面的局部修改.最后讨论了插值函数的一些性质.
A bivariate rational bicubic interpolating spline based on function values with four parameters is constructed, and this spline is with bicubic numerator and biquadratic denominator. The interpolation function has a simple and explicit mathematical representation. The interpolating surface is C^1 in the interpolating region when two parameters satisfy a simple condition, and the interpolating surface can be modified by selecting suitable parameters under the condition that the interpolating data are not changed. Some properties of the interpolation are derived.