curvature versus slope
  n = 1113744 
  X=0, Y = 18.53 +/- 12.85 
  Weighted least-squares fit:  Y = 24.8 + 3.269 X  + -0.03440 X**2 

slope versus dZ, curvature < 5
  n = 136669 
  X=0, Y = 9.15 +/- 2.01 
  Weighted least-squares fit:  Y = 6.1 + 0.364 X  + 0.00037 X**2 
     at X = 100, Y = 46.2 
     effective RMSE xy = 71.9 

slope versus dZ, curvature < 15
  n = 394916 
  X=0, Y = 12.37 +/- 5.35 
  Weighted least-squares fit:  Y = 7.6 + 0.399 X  + 0.00007 X**2 

curvature versus dZ, slope < 10
  n = 107565 
  X=0, Y = 7.83 +/- 5.69 
  Weighted least-squares fit:  Y = 6.6 + 2.492 X  + 0.02097 X**2 


Number of samples 1135836
Max dz = 900
Mean dz = 29
RMS dz = 49.9899989998
100cm = 94.689550252 percentile value of dz