curvature versus slope
  n = 224929 
  X=0, Y = 26.33 +/- 22.33 
  Weighted least-squares fit:  Y = 42.0 + 2.741 X  + -0.03041 X**2 

slope versus dZ, curvature < 5
  n = 47295 
  X=0, Y = 16.55 +/- 5.92 
  Weighted least-squares fit:  Y = 14.2 + 0.131 X  + 0.00354 X**2 
     at X = 100, Y = 62.6 
     effective RMSE xy = 95.8 

slope versus dZ, curvature < 15
  n = 105783 
  X=0, Y = 15.34 +/- 5.99 
  Weighted least-squares fit:  Y = 15.1 + 0.131 X  + 0.00370 X**2 

curvature versus dZ, slope < 10
  n = 37562 
  X=0, Y = 14.59 +/- 6.39 
  Weighted least-squares fit:  Y = 14.2 + 1.610 X  + 0.04305 X**2 


Number of samples 227784
Max dz = 900
Mean dz = 42
RMS dz = 89.2244361148
100cm = 90.7153268008 percentile value of dz