根据已知的三维离散数据（x,y,z）,在MATLAB中利用此函数进行三维曲面拟合，再根据polyval2d得出拟合函数的系数矩阵。,according to 3D discrete datum (x,y,z),use this function in MATLAB to fit 3D surface, and use polyval2d to get coefficient matrix

Geodetic Transformations Set of tools to perform transformations between projection, ellipsoidal and cartesian coordinates in either direction. Included are proj2ell - projection to ellipsoidal ell2cart - ellipsoidal to global cartesian d3t