curvature versus slope
  n = 1047884 
  X=0, Y = 6.86 +/- 5.92 
  Weighted least-squares fit:  Y = 10.6 + 4.467 X  + -0.05712 X**2 

slope versus dZ, curvature < 5
  n = 452687 
  X=0, Y = 6.33 +/- 5.86 
  Weighted least-squares fit:  Y = 7.3 + 0.437 X  + 0.00040 X**2 
     at X = 100, Y = 55.0 
     effective RMSE xy = 85.6 

slope versus dZ, curvature < 15
  n = 687266 
  X=0, Y = 6.67 +/- 6.06 
  Weighted least-squares fit:  Y = 7.9 + 0.487 X  + -0.00040 X**2 

curvature versus dZ, slope < 10
  n = 535327 
  X=0, Y = 8.49 +/- 6.32 
  Weighted least-squares fit:  Y = 8.4 + 2.083 X  + 0.04635 X**2 


Number of samples 1073519
Max dz = 900
Mean dz = 20
RMS dz = 34.263683398
100cm = 97.2320005515 percentile value of dz