curvature versus slope
  n = 3778718 
  X=0, Y = 8.58 +/- 5.92 
  Weighted least-squares fit:  Y = 14.3 + 4.995 X  + -0.05886 X**2 

slope versus dZ, curvature < 5
  n = 1763825 
  X=0, Y = 34.44 +/- 14.06 
  Weighted least-squares fit:  Y = 14.4 + 0.103 X  + 0.00204 X**2 
     at X = 100, Y = 45.1 
     effective RMSE xy = 67.1 

slope versus dZ, curvature < 15
  n = 2564116 
  X=0, Y = 34.44 +/- 14.06 
  Weighted least-squares fit:  Y = 13.7 + 0.209 X  + 0.00115 X**2 

curvature versus dZ, slope < 10
  n = 1877434 
  X=0, Y = 17.97 +/- 12.72 
  Weighted least-squares fit:  Y = 14.9 + 0.696 X  + -0.00135 X**2 


Number of samples 3874031
Max dz = 900
Mean dz = 21
RMS dz = 35.9444015112
100cm = 97.2155875882 percentile value of dz