FROM TH2F
constant
5.043237095385583+-0.21510051209551906
chi2/ndof = 0.8314583535253409
plane
1.031644068103087+-1.4058491183516868
invpt slope = 0.12873065687867125+-0.10948973694863787
theta slope = 3.152266647370734+-1.1366895520841078
chi2/ndof = 0.768390922039993
from tgraph2D
constant
5.833324375348098+-0.2145844591556554
chi2/ndof = 5.203253387982433
plane
5.4863899552594715+-1.3925489240075548
invpt slope = 0.32807915027957857+-0.0938135518949798
theta slope = -0.8352329169406367+-1.1518043619260678
chi2/ndof = 4.73378756166825