DØ Software Frequently Asked Questions

The following collection of "facts" have been randomly collected. If you figure out how to "do something new", and think someone else might be interested, send your FAQ to Laurent Duflot, and it will be added to this page.

Running executables

• Copying events from one file to another
  • To copy events from one file to another, you can use copyd0om.py.
• How to skip events that crash an executable
  • The ReadEvent interface allows users to skip particularly troublesome events, by using the SkipCollids option. For a complete list of options available, see the latest version of ReadEvent.rcp.
• What's the status of a particular build???

ROOT stuff

• Elemer Nagy and Phillipe Canal have provided instructions on how to use ROOT within the DØ framework.
• There is an ABOUT-ROOT mailing list to which you can subscribe. There is also an archive.
• How to merge a bunch of root files (like reco_analyze root tuples).
• How to compile root macros from Daniel Whiteson.
• How to use root with TMB root trees - see the tmb_tree package.
• How to produce "nice looking plots" from Avto Kharchilava.

Developing software

• Ask the release managers and they'll tell you what EVERYONE wants to know...
• A lot of questions have already been answered on the d0rug mailing list, please check the archives
• I'm a new user and when I try to check out a package, I get "You have no tickets cached"...
• Is a release frozen? Find out how to know.
• How to make an optimized executable.
• How to patch a production release.
• How to determine whether an Event is Monte Carlo
  • Use the is_monte_carlo() method in HistorySelector
• Some standard problems using RCP's.
• Hints on modifying RCP's and checking out a CVS package
  • More on Forcing the use of a local RCP script
• An interactive RCP browser exists that can let you find where a given RCP parameter comes from.
• Use the error logger to communicate errors (don't use cout or cerr!)
• I have to create a new chunk, where do I start?
• How to use profiling with gcc
• Some examples of how to avoid writing slow code
• More ways to write fast code (maintained by Heidi Schellman)
• How to use chase memory leaks : valgrind can be used, but is quite slow for major framework executables, totalview is reported to work
• Running Totalview V6 with kai based releases

Analyzing data

• How do I use the runs database and figure out what runs are "physics"?

Using Fermilab computers

• CLUEDØ - the best desktop Linux cluster in the world!

This page maintained by Laurent Duflot