Installing the code on Linux or macOS

Installing the NNPDF code requires a system with a recent version of either a Linux-based operating system or macOS. There are two methods for installing the code, both of which require conda. You can either install the code entirely with conda or install the code from source, with the dependencies still being installed via conda. Installation using conda is preferable if you simply want to run the code, while the Installation from source is necessary if you want to develop the code.

Installation using conda

A helper script exists to aid the configuration using conda. To obtain it use:

mkdir nnpdfgit
cd nnpdfgit
git clone git@github.com:NNPDF/binary-bootstrap.git

Execute the script
```
./binary-bootstrap/bootstrap.sh
```
Path: the conda installer will ask to add the conda bin path to the default $PATH environment variable (by editing your .bashrc file). Confirm this unless you know that you have a specific reason not to. Note that newer versions of conda give the option of having conda available, but not any environment (which you have to enable explicitly by either having conda activate in .bashrc or typing it each time you want to use the environment). On remote machines, the addition to .bashrc should read as follows
```
if shopt -q login_shell; then
    . <path-to-conda>/etc/profile.d/conda.sh
    conda activate
fi
```

the if condition is important because conda activate prints to the standard output, which interferes with commands like scp and rsync.

Note that the script may ask you to perform some actions manually ( e.g. it will not overwrite your existing conda configuration). Please pay attention to the output text of the script.

Installing the NNPDF code

After the helper script has run, navigate to the miniconda3 installation directory, by default this is ~/miniconda3, and run the command

. ./etc/profile.d/conda.sh
conda activate
conda install nnpdf

Note: The installer will set up its own version of the LHAPDF code, with its own path for storing PDFs, which can be seen running lhapdf --help. If you have an existing directory with LHAPDF grids, you may want to either move, symlink or copy them to the new path (depending on whether you want to keep around the older installation). The command for symlinking would be something like:

ln -s <old path>/share/LHAPDF/* <new path>/miniconda3/share/LHAPDF

This will avoid symlinking the existing LHAPDF configuration, which may be corrupted or incompatible. You should make sure only the grid directories are transferred if you copy or move instead.

Installation from source

If you intend to work on the NNPDF code, then installing from source is the recommended installation procedure. Note that the binary-bootstrap.sh should be downloaded and run as explained above, if the user has not already done so.

Setup a conda environment with a recent Python version and, if you don’t have them yet, install lhapdf and pandoc since they are not provided through PyPI. Any recent python version should work, but to get an exact range of the supported Python versions see the Github action workflow files.
```
conda create -n nnpdf_dev lhapdf pandoc
```

Clone the repository

git clone https://github.com/NNPDF/nnpdf.git

Install NNPDF packages and its dependencies (make sure the conda environment is activated)
```
cd nnpdf
conda activate nnpdf_dev
python -m pip install -e .
```
Note

Following the installation steps above will set up a development environment that makes it possible to run and work on the nnpdf code. One may wish to install additional, optional, dependencies. Depending on the specific needs for an environment this can be dependencies that enable the running of the CI test, building the documentations, or performing a QED fit.
python -m pip install -e .[tests,docs,qed]

Using the code with docker

We provide docker images for tag release of the code using GitHub Packages. The docker images contain a pre-configured linux environment with the NNPDF framework installed with the specific tag version. The code is installed using miniconda3.

Please refer to the download and authentication instructions from the NNPDF GitHub Packages.

In order to start the docker image in interactive mode please use docker standard syntax, for example:

docker run -it ghcr.io/nnpdf/nnpdf:<tag_version> bash

This will open a bash shell with the nnpdf environment already activated, with all binaries and scripts from the NNPDF framework.