FROM TH2F
constant
3.4885950697287624+-0.1896441341375486
chi2/ndof = 26.606459051523505
plane
33.901283857570846+-2.381328422866171
invpt slope = -6.052571499997569+-0.16377124939785895
theta slope = 2.0474747260551602+-1.9680596945557824
chi2/ndof = 12.51805791286801
from tgraph2D
constant
31.70294959035802+-2.6607394873326555
chi2/ndof = 729.192068568785
plane
96.84515033088715+-13.042477079474047
invpt slope = -8.015713085745485+-1.103731602045731
theta slope = -38.00474565489316+-11.521304933833836
chi2/ndof = 440.5821978530712