The BUQEYE collaboration presents a pedagogical introduction to projection-based, reduced-order emulators for applications in low-energy nuclear physics. All examples discussed in our Frontiers in Physics Article "BUQEYE Guide to Projection-Based Emulators in Nuclear Physics" (arXiv:2212.04912) and more are available here as interactive, open-source Python code so that practitioners can readily adapt projection-based emulators for their own work.

The documentation is written using Quarto. Download the latest version of Quarto from here and then spin it up in development using

python3 -m venv env
source env/bin/activate
pip3 install -r requirements.txt
export PYTHONPATH=$PYTHONPATH:`pwd`
quarto preview docs

Alternatively, you can spin it up using the management system conda:

conda env create -f environment.yml
conda activate frontiers-emulator-env
pip3 install .
quarto preview docs

The following flags are helpful:

• --no-browser if you are developing in a supported IDE (VS Code)
• --no-watch-inputs if you don't want the docs updating after every save, which is helpful if it takes a long time to build
• --port Choose a default port (e.g., 1234) so that your browser link will not change. This is not necessary because a default is set in the _quarto.yml file.
• Rather than specify docs you can instead use a file name to only render that file.

The files docs/*.qmd contain the sections of our manuscript. The user has these options to take advantage of the interactive content:

• quarto convert docs/[filename].qmd converts the document docs/[filename].qmd to an interactive Jupyter Notebook, which can be evaluated cell by cell.
• one can use any editor or IDE to edit the files docs/*.qmd and let quarto re-render the website on-the-fly using quarto preview docs. VS Code provides an extension for quarto.

A tutorial on using quarto can be found here.

Please cite this repository as:

@article{Drischler:2022ipa,
    author = "Drischler, C. and Melendez, J. A. and Furnstahl, R. J. and Garcia, A. J. and Zhang, Xilin",
    title = "{BUQEYE Guide to Projection-Based Emulators in Nuclear Physics}",
    eprint = "2212.04912",
    archivePrefix = "arXiv",
    primaryClass = "nucl-th",
    month = "12",
    JOURNAL={Front. Phys.},      
    VOLUME={10},
    pages=92931,
    YEAR={2023},      
    URL={https://www.frontiersin.org/articles/10.3389/fphy.2022.1092931},       
    DOI={10.3389/fphy.2022.1092931},    
    note          = {supplemental, interactive Python code can be found on the companion website~\url{https://github.com/buqeye/frontiers-emulator-review}},
    ISSN={2296-424X}   
}

See also our published literature guide Model reduction methods for nuclear emulators.