Axes Label and fitting [pyroot]

I have a root file that that I have to analyse.

bottom = ROOT.TFile(“202001081411_r750_W2-I8-1_pin4_RedBottom_Tune30.dat.root”)
tree_bottom = bottom.Get(“edge”)
c=ROOT.TCanvas()

tree_bottom.Draw(“volt-BlineMean:time-atleft”,“Vbias==30”,“l”)
tree_bottom.SetLineWidth(1)
c.Draw()

I got this plot.

http://i.imgur.com/RvTta3y.png

How can i change the label of the axes.

I tired this

bottom_tree.GetXaxis().SetTitle(“x-something”)

but i get an error “‘TTree’ object has no attribute 'GetXaxis”

And I would also like to do a polynomial fitting

func = ROOT.TF1(‘func’, '[0] + [1]*x ', 0, 10)

How can i implied this fitting function into data set ?


ROOT Version: PyRoot
Platform: Python
Compiler: Not Provided


ree_bottom.Draw(“volt-BlineMean:time-atleft”,“Vbias==30”,“l”)
htemp.GetXaxis().SetTitle("hello")