curvature versus slope
  n = 161418 
  X=0, Y = 19.20 +/- 14.99 
  Weighted least-squares fit:  Y = 42.2 + 2.840 X  + -0.03194 X**2 

slope versus dZ, curvature < 5
  n = 31821 
  X=0, Y = 11.62 +/- 4.64 
  Weighted least-squares fit:  Y = 17.1 + 0.399 X  + 0.00216 X**2 
     at X = 100, Y = 78.5 
     effective RMSE xy = 120.4 

slope versus dZ, curvature < 15
  n = 52316 
  X=0, Y = 11.62 +/- 4.64 
  Weighted least-squares fit:  Y = 16.9 + 0.435 X  + 0.00234 X**2 

curvature versus dZ, slope < 10
  n = 21148 
  X=0, Y = 18.63 +/- 7.57 
  Weighted least-squares fit:  Y = 18.0 + 1.393 X  + 0.05139 X**2 


Number of samples 162613
Max dz = 900
Mean dz = 62
RMS dz = 103.189146716
100cm = 80.385947003 percentile value of dz