关于三次样条插值矩阵的非奇异性

近年来,在计算数学刊物上相继发表了许多篇关于三次插值样条存在唯一性的文章,例如[1-3].这些文章讨论的是三次样条插值矩阵为非奇异的条件.[1]中用的是凑方法,讨论了与插值矩阵相关的另一个对称阵为正定的条件,经过复杂凑方,得到了某些充分条件,[2]是用大块凑方,所得结果形式上异于[1],但实质上是完全相同的.[3]则是对插值矩阵进行一种特殊分解,得出非异的四个充分条件.它不限于[1-2]所讨论的正定情形,因而适用范围更广些.

A NOTE ON NONSINGULARITY OF THE INTERPOLATING MATRIX OF CUBIC SPLINE

Some general conditions for nonsingularity of the interpolating matrix of the cubic sp-line are presented by using eigenvalue analysis techniques. The results have generalized andimproved those in [1], [2], [3].