中文说明：该函数特别适合空间点的曲面拟合，matlab中对于此类数据点似乎只能用griddata差值计算，并且效果不怎么好；至于B样条拟合，其外扩数据点的选取不是一般的matlab用户所能掌握的，同时对于非网格数据的转换也是一个问题
English Description：
This function is particularly suitable for surface fitting points, for this type of data in a MATLAB seems to only use GridData margin calculation, and the effect is not very good; as for b-spline fitting, besides expanding selection of data points is not generally available to MATLAB users, while conversion is also a problem for non-grid data