curvature versus slope
  n = 7508 
  X=0, Y = 13.15 +/- 7.31 
  Weighted least-squares fit:  Y = 13.4 + 1.120 X  + -0.02779 X**2 

slope versus dZ, curvature < 5
  n = 3069 

  Weighted least-squares fit:  Y = 37.4 + -0.044 X  + -0.00240 X**2 
     at X = 100, Y = 9.0 
     Bad fit. P2 = 0
slope versus dZ, curvature < 15
  n = 5520 

  Weighted least-squares fit:  Y = 37.3 + -0.001 X  + -0.00246 X**2 

curvature versus dZ, slope < 10
  n = 3110 
  X=0, Y = 35.71 +/- 16.88 
  Weighted least-squares fit:  Y = 35.3 + 2.082 X  + -0.20260 X**2 


Number of samples 7515
Max dz = 130
Mean dz = 32
RMS dz = 38.0788655293
100cm = 99.7737857618 percentile value of dz