To cite package ‘pdi’ in publications use:

  Finch J (2024). _pdi: Phenotypic Index Measures for Oak Decline
  Severity_. R package version 0.4.2,
  <https://github.com/jasenfinch/pdi>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {pdi: Phenotypic Index Measures for Oak Decline Severity},
    author = {Jasen Finch},
    year = {2024},
    note = {R package version 0.4.2},
    url = {https://github.com/jasenfinch/pdi},
  }