curvature versus slope
  n = 241990 
  X=0, Y = 21.77 +/- 13.28 
  Weighted least-squares fit:  Y = 30.2 + 3.194 X  + -0.03453 X**2 

slope versus dZ, curvature < 5
  n = 70125 
  X=0, Y = 14.16 +/- 14.40 
  Weighted least-squares fit:  Y = 14.0 + 0.516 X  + -0.00156 X**2 
     at X = 100, Y = 50.0 
     effective RMSE xy = 75.4 

slope versus dZ, curvature < 15
  n = 127737 
  X=0, Y = 14.16 +/- 14.40 
  Weighted least-squares fit:  Y = 13.9 + 0.592 X  + -0.00213 X**2 

curvature versus dZ, slope < 10
  n = 21231 
  X=0, Y = 18.20 +/- 13.86 
  Weighted least-squares fit:  Y = 17.9 + 1.223 X  + 0.03254 X**2 


Number of samples 242908
Max dz = 900
Mean dz = 32
RMS dz = 71.0352025407
100cm = 95.2669323365 percentile value of dz