CDF event Display
The CDF event display is slow and incomplete, but offers the best visualisation tool for CDF physics that we have. As input it reads in a generated
root file which can either be at generation or production (dst) level. It
offers a variety of geometric views. Facilities for information retrieval
are primitive at the moment.
Instructions
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Start the event display by typing evd input-file-name.
You can find sample input root files in /scsi10/cdfdata/mc, or you can
generate your own with cdf2sim.
The event display takes an age to start up (this is normal).
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Eventually a small window entitled "CDF ED Manager" pops up. This gives you the option to open/close files/print (under the file menu), and to choose
a geometry to view (under the window menu). I have only used the COT view
so far, so will use this as an example. Don't let this discourage you from trying the other views in case they are of more use to you than this one.
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After having clicked COT, the event display will eventually put up a view of the COT and silicon r-phi geometry. Silicon hits will be displayed in red,
likewise any COT hits; tracks are shown in black. You can quickly zoom in
on any area of the detector by drag and clicking a rectangle around it; the
event display will automatically zoom and redraw. Alternatively, you can use
the zoom buttons.
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Cuts can be applied to the particles shown, so for example if you wanted to get rid of anything that
would not be detected by the silicon, you would cut at |eta|<2.0, and if you wanted reasonable momentum you might apply a minimum pT cut of 2 GeV (all accessed from the Cuts menu).
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The options menu (lower line!)
allows you to toggle MC information and
CDF track information on or off as desired.
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The select buttons actually do allow you to retrieve information; if you
click on the "track" button and then click on a track, the CDF track
parameters corresponding to that track will be printed out to your screen. Be warned though, commands can take a long time to execute.
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When you have finished with one event and want to look at the next, simply
click on the "next" button under "Event Handling" on the left hand side.
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When you have finished and want to
quit the event display, do not forget to to type "quit" at the AC++ prompt. For some reason quitting the event display does not
entirely kill the program and you will hang in some sort of virtual CDF code space unless you do this.
Useful Links