插值算法：插值方法包括：（1）线性插值（2）抛物插值（3）拉格朗日插值。三种方法都是利用离散的数据近似模拟曲线函数走向，从而给出指定离散点对应的函数值。选用不同类型的插值函数，逼近的效果不同，线性插值需要根据给定的两个点，抛物插值需要给定三个点，一般形式则通过拉格朗日插值来求解(Interpolation algorithms: interpolation methods include: (1) linear interpolation (2) parabolic interpolation (3) Lagrange interpolation. The three methods use the discrete data to approximately simulate the curve function trend, and then give the function values corresponding to the designated discrete points. Different interpolation functions are used, and the effect of approximation is different. Linear interpolation needs to give three points according to the given two points, and the general form is solved by Lagrange interpolation)