curvature versus slope
  n = 181458 
  X=0, Y = 10.31 +/- 6.12 
  Weighted least-squares fit:  Y = 10.4 + 4.728 X  + -0.05399 X**2 

slope versus dZ, curvature < 5
  n = 110840 
  X=0, Y = 24.14 +/- 7.83 
  Weighted least-squares fit:  Y = 39.9 + -0.289 X  + 0.00521 X**2 
     at X = 100, Y = 63.2 
     effective RMSE xy = 76.9 

slope versus dZ, curvature < 15
  n = 161676 
  X=0, Y = 24.14 +/- 7.83 
  Weighted least-squares fit:  Y = 40.6 + -0.186 X  + 0.00340 X**2 

curvature versus dZ, slope < 10
  n = 101508 
  X=0, Y = 34.34 +/- 24.94 
  Weighted least-squares fit:  Y = 36.2 + 4.196 X  + -0.16485 X**2 


Number of samples 182148
Max dz = 700
Mean dz = 31
RMS dz = 43.4050688284
100cm = 97.7721413356 percentile value of dz