FROM TH2F
constant
18.70513837612791+-0.5283759739567854
chi2/ndof = 4.002970499095423
plane
10.74029327527002+-1.2399506306081636
invpt slope = 4.156817747713111+-0.7614035611777114
theta slope = 7.232123064782049+-1.6503223490532783
chi2/ndof = 3.32916883592178
from tgraph2D
constant
21.065867373272322+-1.051086391417731
chi2/ndof = 91.69695597354159
plane
7.21870626183179+-1.5312655859246735
invpt slope = 6.175110202822465+-0.8852238364639698
theta slope = 15.779428008557002+-2.1540861743027326
chi2/ndof = 40.631561415075154