FROM TH2F
constant
11.631445816173803+-0.3635595147026206
chi2/ndof = 9.962424163499556
plane
12.26675558135854+-0.8249056231405926
invpt slope = 1.1679341342157625+-0.4361286859926222
theta slope = -2.7826312484171214+-0.8893017478376459
chi2/ndof = 10.030481832168949
from tgraph2D
constant
19.47985093838583+-2.1140824200205217
chi2/ndof = 478.2198589971402
plane
3.7170671224534537+-4.20141970992305
invpt slope = 10.780723773979137+-2.194922684293362
theta slope = 7.365629610331003+-4.811388027176355
chi2/ndof = 384.6596086253007