I am trying to draw a vertical line in 2D graph. However, line is not showing up for some reason. I am trying to draw line from x-axis 47 to all the way to top of the y-axis. Here is my code:

```
g = ROOT.TGraph2D()
for x in range(128):
for y in range(645):
z = adc13[x][y]
g.SetPoint(x + 128 * y,x,y,z)
line = ROOT.TLine(47,0,47,644) #x1,y1,x2,y2
line.GetColor(1)
c1 = ROOT.TCanvas("c1")
g.Draw("TRI2 Z")
ROOT.gPad.Update()
g.SetTitle("Muon Tracks")
g.GetXaxis().SetTitle("Channel Number")
g.GetYaxis().SetTitle("Time Ticks")
g.GetZaxis().SetTitle("ADC")
c1.SetTheta(0.0+90)
c1.SetPhi(0.0+0.001)
ROOT.gStyle.SetHistTopMargin(0)
c1.Draw()
```