curvature versus slope
  n = 40906 
  X=0, Y = 9.15 +/- 7.10 
  Weighted least-squares fit:  Y = 13.1 + 4.927 X  + -0.06179 X**2 

slope versus dZ, curvature < 5
  n = 21135 
  X=0, Y = 19.82 +/- 2.22 
  Weighted least-squares fit:  Y = 19.8 + 0.094 X  + 0.00369 X**2 
     at X = 100, Y = 66.1 
     effective RMSE xy = 99.1 

slope versus dZ, curvature < 15
  n = 30773 
  X=0, Y = 21.19 +/- 3.88 
  Weighted least-squares fit:  Y = 19.0 + 0.297 X  + 0.00168 X**2 

curvature versus dZ, slope < 10
  n = 23241 
  X=0, Y = 20.02 +/- 4.27 
  Weighted least-squares fit:  Y = 19.9 + 0.196 X  + 0.21944 X**2 


Number of samples 41538
Max dz = 900
Mean dz = 30
RMS dz = 54.083269132
100cm = 96.0734748905 percentile value of dz