For those NEW to using ROOT

From: Kevin McIlhany (mcilhany@usna.edu)
Date: Sun Jul 21 2002 - 20:51:04 EDT


Many of you might be new to using root. I was about two weeks ago. Here's a crash course:

1) Log onto a useful machine such as dblast08, dblast09 or perhaps spud1 or spud5 as blast
2) cd to /home/blast/blast/commis/phase1/RESULTS
3) type: root
4) Type: TFile f("ep_2pass_400-728.root")
        This command opens the file
5) Type: f->ls()
        This command lists which objects are in the
        file that you can play with. For this example
        file, you will find an ntuple called: "ep"
6) Type: ep->Print()
        This command prints the varaibles which make up
        the ntuple "ep"
7) Type: ep->Draw("tof1")
        This command draws a histogram of the varaible
        "tof1" - which is the paddle number of the
        first track hit for this event
8) Type: ep->Draw("tof1:tof2")
        Draws a scatter plot of tof1 versus tof2
9) Type: ep->Draw("tofttop1")
        Draws a histogram of TOF, TDC, top #1
10>Type: ep->Draw("(tofttop1+toftbot1)/2:run")
        Draws the mean TDC time for the #1 track versus
        run number.

This should get you started. Take a look in the menus for options to save and print your
results.

Hope this helps,
  -Kevin

The variables for my ntuple are:
The variables are: ntof, ncer = # of tracks read out for the tof and cerenkov detectors.
   sect1, sect2 = which sector each track was found in
   tof1, tof2 = which paddle in the tof that was hit
   cer1, cer2 = which box in the cerenkov that was hit
   tofttop1,... = TOF tdc top/bot detector for track 1 or2
   tofatop1,... = TOF adc top/bot detector for track 1 or2
   cert1, cert2 = cernekov tdc for track 1 or 2
   cera1, cera2 = cerenkov adc for track 1 or 2
   run = run number
   time = unix time, number of seconds since Jan1, 1970



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