curvature versus slope
  n = 650914 
  X=0, Y = 10.54 +/- 9.10 
  Weighted least-squares fit:  Y = 15.9 + 4.280 X  + -0.04932 X**2 

slope versus dZ, curvature < 5
  n = 298992 
  X=0, Y = 13.86 +/- 6.48 
  Weighted least-squares fit:  Y = 8.0 + 1.034 X  + -0.00367 X**2 
     at X = 100, Y = 74.7 
     effective RMSE xy = 116.7 

slope versus dZ, curvature < 15
  n = 482167 
  X=0, Y = 13.88 +/- 6.55 
  Weighted least-squares fit:  Y = 8.0 + 1.061 X  + -0.00422 X**2 

curvature versus dZ, slope < 10
  n = 323435 
  X=0, Y = 12.96 +/- 7.23 
  Weighted least-squares fit:  Y = 11.2 + 2.589 X  + 0.04852 X**2 


Number of samples 661249
Max dz = 900
Mean dz = 24
RMS dz = 44.8887513749
100cm = 96.6241158777 percentile value of dz