curvature versus slope
  n = 78299 
  X=0, Y = 14.24 +/- 10.52 
  Weighted least-squares fit:  Y = 28.5 + 3.359 X  + -0.03618 X**2 

slope versus dZ, curvature < 5
  n = 24969 
  X=0, Y = 8.58 +/- 6.38 
  Weighted least-squares fit:  Y = 6.6 + 0.041 X  + 0.00362 X**2 
     at X = 100, Y = 46.9 
     effective RMSE xy = 72.9 

slope versus dZ, curvature < 15
  n = 36763 
  X=0, Y = 8.58 +/- 6.38 
  Weighted least-squares fit:  Y = 5.0 + 0.313 X  + 0.00137 X**2 

curvature versus dZ, slope < 10
  n = 20639 
  X=0, Y = 6.55 +/- 4.20 
  Weighted least-squares fit:  Y = 5.8 + 1.569 X  + 0.06536 X**2 


Number of samples 78605
Max dz = 900
Mean dz = 40
RMS dz = 152.42375143
100cm = 91.5768717003 percentile value of dz