FROM TH2F
constant
13.564578652971695+-0.30172411381894415
chi2/ndof = 20.273285719337526
plane
8.306985869020302+-0.6876471679566148
invpt slope = 3.5000135221802684+-0.2218566536674783
theta slope = -3.7359416134199925+-0.9938044277456888
chi2/ndof = 18.830681572336367
from tgraph2D
constant
31.241212675623743+-3.641753253998944
chi2/ndof = 2188.290517133962
plane
-4.495364794391048+-6.97991844680267
invpt slope = 16.632909917210167+-1.7238193932218926
theta slope = -6.141290188337461+-9.540313912008422
chi2/ndof = 1402.8693184100234