curvature versus slope
  n = 987810 
  X=0, Y = 10.89 +/- 6.69 
  Weighted least-squares fit:  Y = 9.8 + 4.454 X  + -0.04859 X**2 

slope versus dZ, curvature < 5
  n = 503231 
  X=0, Y = 40.96 +/- 20.12 
  Weighted least-squares fit:  Y = 48.6 + -0.200 X  + 0.00005 X**2 
     at X = 100, Y = 29.0 
     Bad fit. P2 = 0
slope versus dZ, curvature < 15
  n = 792476 
  X=0, Y = 40.25 +/- 18.93 
  Weighted least-squares fit:  Y = 50.6 + -0.416 X  + 0.00331 X**2 

curvature versus dZ, slope < 10
  n = 494830 
  X=0, Y = 47.63 +/- 27.12 
  Weighted least-squares fit:  Y = 45.2 + 2.151 X  + -0.03605 X**2 


Number of samples 991286
Max dz = 900
Mean dz = 38
RMS dz = 49.9699909946
100cm = 97.3233758976 percentile value of dz