插值和拟合都是函数逼近或者数值逼近的重要组成部分。他们的共同点都是通过已知一些离散点集M上的约束，求取一个定义在连续集合S的未知连续函数，从而达到获取整体规律目的，即通过"窥几斑"来达到"知全豹"。-Interpolation and fitting function approximation or are an important part of the numerical approximation. They have in common are constrained by the known number of discrete points on the M strike a definition of continuous collection S (M contained in S) unknown continuous function, so as to achieve the purpose of obtaining the whole law, namely through the "peep a few spots "to achieve" know the whole picture. "