curvature versus slope
  n = 163572 
  X=0, Y = 11.82 +/- 12.30 
  Weighted least-squares fit:  Y = 20.1 + 4.467 X  + -0.04971 X**2 

slope versus dZ, curvature < 5
  n = 134916 
  X=0, Y = 33.92 +/- 8.06 
  Weighted least-squares fit:  Y = 34.6 + -0.539 X  + 0.00589 X**2 
     at X = 100, Y = 39.5 
     effective RMSE xy = 30.2 

slope versus dZ, curvature < 15
  n = 155511 
  X=0, Y = 34.12 +/- 8.06 
  Weighted least-squares fit:  Y = 34.6 + -0.514 X  + 0.00593 X**2 

curvature versus dZ, slope < 10
  n = 131638 
  X=0, Y = 33.54 +/- 7.50 
  Weighted least-squares fit:  Y = 33.5 + 0.574 X  + 0.04430 X**2 


Number of samples 164116
Max dz = 900
Mean dz = 32
RMS dz = 57.3498038358
100cm = 99.3754417607 percentile value of dz