Data Analysis - Starting Out

Starting Out

The Overview section should be viewed before starting this section. (Currently under construction)

---

The purpose of this section is to give new members of the XEM group hands-on experience with 'hcana' and the 'replay'. A bare-bones git branch named practice has been added to the hallc_replay_XEM repository.

If none of this makes sense, make sure you have followed along with the getting started software section.

It is recommended all practice be performed in a separate directory on your /group/ disk such as:
/group/c-xem2/<CUE_username>/PRACTICE/
The practice branch is used for practice, and is not meant to be your long-term analysis branch. You should be on the master branch to get the most up-to-date calibrations. If performing a new calibration or contributing to the hallc_replay_XEM, new work should be added to a new_feature_branch and merged into your origin. This is followed by a push to mrcmor100. Refer to the git help and software overview sections to familiarize yourself with this workflow.

By the time you have finished the practice, you should be familiar with the naming conventions, location of specific parameters, and be able to follow naming conventions. You should not make pull requests to Casey. If you want him to check something you have done while practicing, push the local changes to your origin and notify Casey via Slack.

What to Learn

• How to setup your practice directory
  • Setting all hallc_replay_XEM directories
• What are the standard.kinematics and standard.database files?
• How do I include parameters in hcana?
  • What are the naming conventions for hcana?
• Running your first replay
• Show what the value of a parameter is in hcana

Setting up directories

git clone git@github.com:<username>/hallc_replay_XEM.git into your /group/PRACTICE/ disk location
Username should be your github username. Follow along with the software section of getting started if you have not yet forked the hallc_replay_XEM repository from mrcmor100.

1. Go into the hallc_replay_XEM directory
   

git submodule init
git submodule update
git fetch origin comparisons
git checkout comparisons

Now you should have all the submodules used in the hallc_replay_XEM directory and you should be on the comparisons branch. Check this by typing git branch.

We must make the ROOTfiles and REPORT_OUTPUT directories on the /volatile/ disk to prevent using the /group/ location inappropriately. These directories are then symbolicly linked to the /volatile/ directories. They can have any name you like on the /volatile/ disk, but for the scripts to work properly in hallc_replay_XEM you will need them to have the names ROOTfiles and REPORT_OUTPUT.

mkdir /volatile/hallc/xem2/<CUE_username>/<desired_rootfiles_name> mkdir /volatile/hallc/xem2/<CUE_username>/<desired_report_output_name> ln -s /volatile/hallc/xem2/<CUE_username>/<desired_rootfiles_name> ROOTfiles ln -s /volatile/hallc/xem2/<CUE_username>/<desired_report_output_name> REPORT_OUTPUT

We must now add the subdirectories to take the output from our hallc_replay_XEM scripts. These are as follows:

1. ROOTfiles/SHMS/
   1. ROOTfiles/SHMS/CALIBRATION
   2. ROOTfiles/SHMS/PRODUCTION
   3. ROOTfiles/SHMS/TIMING
   4. ROOTfiles/SHMS/SCALERS
2. ROOTfiles/HMS/
   1. ROOTfiles/HMS/CALIBRATION
   2. ROOTfiles/HMS/PRODUCTION
   3. ROOTfiles/HMS/TIMING
   4. ROOTfiles/HMS/SCALERS

The CALIBRATION directories are used for running the calibration SCRIPTS. The TIMING directories are to hold the output of the SCRIPTS in SCRIPTS/TIMING, etc. These calibrations, timing, production, and scaler scripts are explained in more detail on the other pages of the data analysis pages.

Now we must point the hallc_replay_XEM to the raw EVIO data files. This is done by adding the appropriate /raw directories:

ln -s /cache/mss/hallc/spring17/raw raw-sp18 ln -s /cache/mss/hallc/jpsi-007/raw raw-sp19

The files may not be here at all times. This is the front face of the tape library. For more information refer to the scicomp documentation and the file structure and farm sections of getting started to use the jcace utility.

Naming Conventions

hallc_replay_XEM is a framework of calibration files, replay scripts and database files that point the hallc analyzer (hcana) to the appropriate data files.

Standard Database and Standard Kinematics

standard.database is spectrometer specific file, and points the analyzer to run-specific calibrations. You can find these files in the DBASE directory as:

DBASE/<spec>/standard.database

• The semicolons in PARAM files and DBASE files are comments
• The word #include is recognized as a special word. The analyzer will read these files in similar to how standard.database. Each

Overview of a SCRIPT