curvature versus slope
  n = 865049 
  X=0, Y = 29.69 +/- 26.38 
  Weighted least-squares fit:  Y = 43.6 + 2.746 X  + -0.02959 X**2 

slope versus dZ, curvature < 5
  n = 127434 
  X=0, Y = 7.47 +/- 5.42 
  Weighted least-squares fit:  Y = 9.8 + 0.077 X  + 0.00051 X**2 
     at X = 100, Y = 22.6 
     effective RMSE xy = 32.0 

slope versus dZ, curvature < 15
  n = 244379 
  X=0, Y = 7.47 +/- 5.42 
  Weighted least-squares fit:  Y = 9.8 + 0.195 X  + 0.00079 X**2 

curvature versus dZ, slope < 10
  n = 128599 
  X=0, Y = 8.49 +/- 5.41 
  Weighted least-squares fit:  Y = 8.7 + 2.131 X  + -0.10970 X**2 


Number of samples 878787
Max dz = 900
Mean dz = 38
RMS dz = 60.1331855135
100cm = 90.8440839475 percentile value of dz