curvature versus slope
  n = 1149562 
  X=0, Y = 9.49 +/- 7.10 
  Weighted least-squares fit:  Y = 18.3 + 4.479 X  + -0.05215 X**2 

slope versus dZ, curvature < 5
  n = 477707 
  X=0, Y = 8.31 +/- 4.77 
  Weighted least-squares fit:  Y = 15.5 + 0.247 X  + 0.00257 X**2 
     at X = 100, Y = 65.9 
     effective RMSE xy = 100.6 

slope versus dZ, curvature < 15
  n = 712659 
  X=0, Y = 8.73 +/- 4.85 
  Weighted least-squares fit:  Y = 15.8 + 0.333 X  + 0.00220 X**2 

curvature versus dZ, slope < 10
  n = 558034 
  X=0, Y = 15.33 +/- 10.80 
  Weighted least-squares fit:  Y = 16.5 + 1.725 X  + -0.02499 X**2 


Number of samples 1167939
Max dz = 900
Mean dz = 31
RMS dz = 56.73623181
100cm = 93.3390356859 percentile value of dz