FROM TH2F
constant
13.6832875340015+-0.5339180561765211
chi2/ndof = 8.01601518477056
plane
0.32975935997194794+-1.2902988846862635
invpt slope = 14.032898677781438+-1.0702569740006092
theta slope = 7.577127326846094+-1.9510377006858313
chi2/ndof = 4.375338768450837
from tgraph2D
constant
18.383093111582383+-2.447694097032098
chi2/ndof = 371.45479592857424
plane
3.5211668644447465+-4.213175429580426
invpt slope = 16.988452846079923+-2.964568405287055
theta slope = 5.091525557449706+-7.0601470682421645
chi2/ndof = 245.33418677487646