sgsdf_2d2

代码说明：

  2D Savitzky-Golay Smoothing Differentiation Filter(2-D Savitzky-Golay (SG) Smoothing and Differentiation Filter. The filter coefficients are calculated from the decomposation property of the 2-D SG filters. In addition, the filter coefficients for mixed partial derivative can be obtained by this function. h=sgsdf_2d3(x,y,nx,ny,d,flag_coupling)x = x data point, e.g.,-3:3 (both odd-length)