DDT Event Display

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DDT Event Display was made to display tracks taken from ddt files (in contrast with usual EventDisplay which takes artdaq files as input). The goal as to create event display able to work with ddt data format and able to display tracks. Also, for certain tasks it's useful to have tool, displaying tracks in 3D format. DDT Event Display was meant to solve these problems, to be easy to use, independent from any frameworks and operational systems. That's why it was chosen to be written in JavaScript and to be run in browser.

Architecture of DDT Event Display:

  • Front-end: js code and html/css markup
  • Back-end: module (DDTEventDisplay) to produce displayable data in right format
  • Data in text form


You need to download data file to your computer, then open Event Display page and drag&drop file there.
Producing your own file includes running DDTEventDisplay module: just run nova -c ddtevd.fcl -s <your DDT file> and it will produce DDTEvdData.txt to a directory you run it from (i.e. $PWD).
Note that datafile for full file, say, from cosmic pulser, would weight ~350 Mb (~3000 events, each contains ~100 tracks). Front-end part was checked to work up to 150 Mb files, so it's better idea to take some number of events (running DDTEventDisplay module with -n 10 or so) and run through them.

Front end is pretty self-explanatory, but in case something doesn't work, here are pictures of how it looks like:

One useful note is that you can save some tracks for list (displayed in the right part) and then load new file - saved tracks will stay on the page!

It's interesting to compare data displayed in DDT event display and artdaq Event Display:

They coincide, so DDT Event Display works. So not so interesting. I was lying.

Technical details

Libraries used:
  • THREE js – 3D visualization
  • D3JS – making histograms
  • jQuery – hiding/showing elements to switch between views + easy access to html elements
  • Bootstrap – css library for better markup

Where to find it

Here you can find repo with DDT event display module (it produces the text file with necessary format). Also, here you can find html file with the view of the DDT Event Display. All underlying JavaScript and CSS libraries are in js/ folder