说明：  三次B－Spline 好用，可根据您自己的X 与 Y 进行任意插值。插值与matlab差距很小，保证用一次您就会喜欢！绝对，吐血推荐！
(Cubic B-Spline easy to use, according to your own X and Y arbitrary interpolation. Interpolation with matlab gap is very small to ensure that time you will like! Absolute, the recommended blood!)