curvature versus slope
  n = 1368721 
  X=0, Y = 10.85 +/- 8.07 
  Weighted least-squares fit:  Y = 14.6 + 4.733 X  + -0.05475 X**2 

slope versus dZ, curvature < 5
  n = 612010 
  X=0, Y = 8.81 +/- 4.65 
  Weighted least-squares fit:  Y = 13.7 + 0.131 X  + 0.00260 X**2 
     at X = 100, Y = 52.8 
     effective RMSE xy = 80.1 

slope versus dZ, curvature < 15
  n = 998258 
  X=0, Y = 8.81 +/- 4.65 
  Weighted least-squares fit:  Y = 13.2 + 0.262 X  + 0.00178 X**2 

curvature versus dZ, slope < 10
  n = 727347 
  X=0, Y = 14.13 +/- 9.00 
  Weighted least-squares fit:  Y = 14.2 + 0.870 X  + 0.06219 X**2 


Number of samples 1397232
Max dz = 900
Mean dz = 23
RMS dz = 44.3395985548
100cm = 96.2128694447 percentile value of dz