curvature versus slope
  n = 1274475 
  X=0, Y = 14.34 +/- 13.52 
  Weighted least-squares fit:  Y = 43.0 + 2.791 X  + -0.02989 X**2 

slope versus dZ, curvature < 5
  n = 95983 
  X=0, Y = 5.32 +/- 2.71 
  Weighted least-squares fit:  Y = 8.1 + 0.215 X  + 0.00026 X**2 
     at X = 100, Y = 32.2 
     effective RMSE xy = 49.0 

slope versus dZ, curvature < 15
  n = 161535 
  X=0, Y = 5.07 +/- 2.50 
  Weighted least-squares fit:  Y = 8.0 + 0.352 X  + 0.00057 X**2 

curvature versus dZ, slope < 10
  n = 108767 
  X=0, Y = 7.53 +/- 5.74 
  Weighted least-squares fit:  Y = 7.7 + 2.366 X  + -0.11309 X**2 


Number of samples 1291538
Max dz = 900
Mean dz = 59
RMS dz = 87.4070935336
100cm = 79.7577771618 percentile value of dz