curvature versus slope
  n = 65923 
  X=0, Y = 25.39 +/- 23.93 
  Weighted least-squares fit:  Y = 63.8 + 1.502 X  + -0.01595 X**2 

slope versus dZ, curvature < 5
  n = 5368 
  X=0, Y = 9.43 +/- 6.98 
  Weighted least-squares fit:  Y = 9.4 + 0.116 X  + 0.00289 X**2 
     at X = 100, Y = 49.8 
     effective RMSE xy = 76.8 

slope versus dZ, curvature < 15
  n = 11595 
  X=0, Y = 9.77 +/- 6.19 
  Weighted least-squares fit:  Y = 9.2 + 0.211 X  + 0.00194 X**2 

curvature versus dZ, slope < 10
  n = 2801 
  X=0, Y = 9.62 +/- 5.86 
  Weighted least-squares fit:  Y = 9.8 + 1.465 X  + -0.02044 X**2 


Number of samples 67019
Max dz = 900
Mean dz = 51
RMS dz = 96.5297881485
100cm = 86.9156507856 percentile value of dz