curvature versus slope
  n = 392962 
  X=0, Y = 48.55 +/- 32.77 
  Weighted least-squares fit:  Y = 58.0 + 2.729 X  + -0.03701 X**2 

slope versus dZ, curvature < 5
  n = 267607 
  X=0, Y = 14.12 +/- 6.59 
  Weighted least-squares fit:  Y = 10.5 + 0.497 X  + 0.00296 X**2 
     at X = 100, Y = 89.8 
     effective RMSE xy = 140.1 

slope versus dZ, curvature < 15
  n = 359053 
  X=0, Y = 14.96 +/- 7.13 
  Weighted least-squares fit:  Y = 10.8 + 0.515 X  + 0.00296 X**2 

curvature versus dZ, slope < 10
  n = 93853 
  X=0, Y = 13.67 +/- 7.25 
  Weighted least-squares fit:  Y = 13.7 + 0.105 X  + 0.33725 X**2 


Number of samples 394376
Max dz = 900
Mean dz = 44
RMS dz = 57.0175411606
100cm = 93.8715844778 percentile value of dz