ROOT

The artemis and artemis_crib tools are built based on the ROOT library. Before installing these tools, you must install ROOT on your system.

Why Build ROOT from Source?

Since artemis and artemis_crib may depend on a specific version of ROOT, it is recommended to build ROOT from source rather than using a package manager. This approach ensures compatibility and access to all required features.

Steps to Build ROOT from Source

Navigate to the directory where you want to install ROOT:
```
cd /path/to/installation
```

Clone the ROOT repository:

git clone https://github.com/root-project/root.git root_src

Checkout the desired version (replace <branch name> and <tag name> with the specific version):
```
cd root_src
git switch -c <branch name> <tag name>
cd ..
```
Create build and installation directories, and configure the build:
```
mkdir <builddir> <installdir>
cd <builddir>
cmake -DCMAKE_INSTALL_PREFIX=<installdir> -Dmathmore=ON ../root_src
```
- Set mathmore to ON because artemis relies on this library for advanced mathematical features.
Compile and install ROOT:
```
cmake --build . --target install -- -j4
```
- Adjust the -j option based on the number of CPU cores available (e.g., -j8 for 8 cores) to optimize the build process.
Set up the ROOT environment:
```
source <installdir>/bin/thisroot.sh
```
- Replace <installdir> with the actual installation directory.
- Running this command loads the necessary environment variables for ROOT.

Persisting the Environment Setup

To avoid running the source command manually each time, add it to your shell configuration file (e.g., .zshrc or .bashrc):

echo 'source <installdir>/bin/thisroot.sh' >> ~/.zshrc
source ~/.zshrc

This ensures that the ROOT environment is automatically loaded whenever a new shell session starts.

Important Note for pyROOT Users

If you plan to use pyROOT, make sure your Python environment is set up before proceeding with the ROOT installation. Refer to the Python Setting section for detailed instructions on setting up Python and managing virtual environments.

Additional information