curvature versus slope
  n = 50456 
  X=0, Y = 4.95 +/- 4.01 
  Weighted least-squares fit:  Y = 12.8 + 4.500 X  + -0.05000 X**2 

slope versus dZ, curvature < 5
  n = 31812 
  X=0, Y = 94.22 +/- 49.71 
  Weighted least-squares fit:  Y = 73.2 + -1.695 X  + 0.01169 X**2 
     at X = 100, Y = 20.6 
     Bad fit. P2 = 0
slope versus dZ, curvature < 15
  n = 35474 
  X=0, Y = 94.22 +/- 49.71 
  Weighted least-squares fit:  Y = 75.0 + -1.244 X  + 0.01032 X**2 

curvature versus dZ, slope < 10
  n = 30932 
  X=0, Y = 76.85 +/- 55.76 
  Weighted least-squares fit:  Y = 76.6 + -3.735 X  + -0.11665 X**2 


Number of samples 50852
Max dz = 900
Mean dz = 58
RMS dz = 84.9941174435
100cm = 63.258082278 percentile value of dz