说明：  一个ＭＡＴＬＡＢ源函数，用来计算插值，可以选择使用线性，三次样条插值，Hermite插值等方法，希望对大家有用。
(A MATLAB source function, used to calculate the interpolation, you can choose to use linear, cubic spline interpolation, Hermite interpolation, in the hope that useful.)