Layout of the analysis package

Last update: 20 Nov 2024 [History] [Edit]

dir tutorial/AnalysisTutorial/source/MyAnalysis

Now let’s look at the package that you cloned. Your analysis package could be named anything you want, but be aware that the rest of the tutorial assumes this name and would need to be updated according. For now, it is probably best to stick with this name.

Let’s look at the basic package directory structure:

  • MyAnalysis: This is where all of your (public) C++ header files go. By ATLAS convention it is always named the same as the package itself. This makes it easy for users to identify what package a header file goes with.

  • Root: This is where most of your C++ source files go, as well as any private header files. A private header file is a header file that your users do not need to include, e.g. an interface definition would be a public header file while the actual implementation would be in a private header file. If you have no clue what we are talking about here, don’t worry about it for now.

  • src: This is where Athena-specific C++ source files and private header files go. Generally, files in Root are visible in both Athena and AnalysisBase, while files in src are only visible in Athena. We are not actually creating any Athena source files in this tutorial, but it doesn’t hurt to have the directories already. It also contains a sub-directory src/components which holds the source files for component libraries. The latter are used if you go through the Athena path of this tutorial, and will be discussed when setting up an algorithm.

  • share: This is where configuration and small data files go that you need to pick up at run time. Note as these files will be recorded by your version control system this should really only contain small files, and ideally no binary files (e.g. text files are OK, but ROOT files should be avoided). Particularly if this package is meant to go into the offline release, there are strict restrictions as to what you can put in there.

  • python: This is where python modules go. In particular, files here are used to schedule predefined algorithms that should be executed in addition to your analysis algorithm.

There is also another CMakeLists.txt file inside the package. This contains the information about how the package gets compiled. We will look at it in more detail in the next section.

Tip After compilation, python modules in your package will be visible in standard python. For example, you will be able to execute import MyAnalysis.MyModuleName in python.