FROM TH2F
constant
35.14381840184609+-0.5323700694133833
chi2/ndof = 19.263491387722816
plane
35.77750997311113+-2.8032177875291717
invpt slope = -9.678512686821886+-0.27473757329831805
theta slope = 39.675805441803696+-2.636204272966003
chi2/ndof = 9.18439826229677
from tgraph2D
constant
55.22983026315766+-2.7229378764287135
chi2/ndof = 963.8707901009737
plane
59.260983343392255+-11.97809544870822
invpt slope = -9.558117501869791+-0.9705840572710634
theta slope = 25.519701372919002+-10.799201010164808
chi2/ndof = 554.302961856573