 Often it is used to create a 3D surface from a point cloud through either downsampling or upsampling.Consider a function formula_1 and a set of sample points formula_2.Then, the moving least square approximation of degree formula_3 at the point formula_4 is formula_5 where formula_6 minimizes the weighted least-square error 
over all polynomials formula_8 of degree formula_3 in formula_10.