curvature versus slope
  n = 72398 
  X=0, Y = 9.88 +/- 10.09 
  Weighted least-squares fit:  Y = 33.0 + 3.361 X  + -0.03792 X**2 

slope versus dZ, curvature < 5
  n = 21300 
  X=0, Y = 3.51 +/- 4.37 
  Weighted least-squares fit:  Y = 8.8 + 1.270 X  + -0.00586 X**2 
     at X = 100, Y = 77.2 
     effective RMSE xy = 120.4 

slope versus dZ, curvature < 15
  n = 29630 
  X=0, Y = 3.51 +/- 4.37 
  Weighted least-squares fit:  Y = 10.2 + 1.165 X  + -0.00414 X**2 

curvature versus dZ, slope < 10
  n = 18747 
  X=0, Y = 12.08 +/- 10.93 
  Weighted least-squares fit:  Y = 13.2 + 7.264 X  + -0.43876 X**2 


Number of samples 73285
Max dz = 900
Mean dz = 57
RMS dz = 101.990195607
100cm = 82.6854062905 percentile value of dz