curvature versus slope
  n = 1884930 
  X=0, Y = 9.08 +/- 7.21 
  Weighted least-squares fit:  Y = 13.5 + 4.885 X  + -0.05619 X**2 

slope versus dZ, curvature < 5
  n = 1152583 
  X=0, Y = 5.00 +/- 3.99 
  Weighted least-squares fit:  Y = 6.0 + 0.110 X  + 0.00212 X**2 
     at X = 100, Y = 38.1 
     effective RMSE xy = 59.1 

slope versus dZ, curvature < 15
  n = 1526796 
  X=0, Y = 5.29 +/- 4.26 
  Weighted least-squares fit:  Y = 5.7 + 0.260 X  + 0.00079 X**2 

curvature versus dZ, slope < 10
  n = 1258906 
  X=0, Y = 5.75 +/- 3.85 
  Weighted least-squares fit:  Y = 5.6 + 1.435 X  + 0.10582 X**2 


Number of samples 1916311
Max dz = 900
Mean dz = 13
RMS dz = 28.6006992922
100cm = 98.1767051382 percentile value of dz