curvature versus slope
  n = 439664 
  X=0, Y = 13.18 +/- 11.09 
  Weighted least-squares fit:  Y = 20.2 + 4.222 X  + -0.04852 X**2 

slope versus dZ, curvature < 5
  n = 211932 
  X=0, Y = 7.94 +/- 4.71 
  Weighted least-squares fit:  Y = 5.8 + 0.289 X  + 0.00134 X**2 
     at X = 100, Y = 48.1 
     effective RMSE xy = 75.0 

slope versus dZ, curvature < 15
  n = 306383 
  X=0, Y = 7.64 +/- 4.68 
  Weighted least-squares fit:  Y = 5.7 + 0.339 X  + 0.00082 X**2 

curvature versus dZ, slope < 10
  n = 203325 
  X=0, Y = 7.50 +/- 5.18 
  Weighted least-squares fit:  Y = 6.3 + 1.660 X  + 0.03487 X**2 


Number of samples 448524
Max dz = 900
Mean dz = 16
RMS dz = 35.4964786986
100cm = 97.7994488589 percentile value of dz