EVD Basics


The event display is a handy tool for viewing our data events. It is a rot GUI designed to display information in the same physical layout as our detector. It should be used because it displays the data in a way the shows you directly what the data looks like which can't be seen by simply looking at plots of reconstruction variables.


The event display lives in two offline packages, EventDisplay and EventDisplayBase. Like all offline packages, you do NOT have to have a copy of it in your local test release in order to run it. The only file that you may want is the evd_services.fcl file which defines all of the default drawing options. You can copy it to your local test release by doing the following. With your offline environment set up, from the base of your test release, do:

cp $SRT_PUBLIC_CONTEXT/EventDisplay/evd_services.fcl job/.

How to edit this to set your own default drawing options is explained in the EVD tutorial (the docDB linked to at the bottom.)


After setting up your offline environment, execute:

nova -c evd.fcl {filename}.root

Another handy tool is the event dump module. This gives you a list of what data products have been put into a file and what modules put them there. This is handy if you want the EVD to draw any reconstruction products (which you will need to identify by label.) To run event dump, execute:

nova -c eventdump.fcl {filename}.root


There are lots of examples found in the EVD tutorial (see the docDB linked below.)

Resources and Extended Information

  • EVD tutorial - docDB 10991