To cite package ‘pdi’ in publications use:

Finch J (2021). pdi: Phenotypic Index Measures for Oak Decline Severity. R package version 0.4.2, https://github.com/jasenfinch/pdi.

Corresponding BibTeX entry:

  @Manual{,
    title = {pdi: Phenotypic Index Measures for Oak Decline Severity},
    author = {Jasen Finch},
    year = {2021},
    note = {R package version 0.4.2},
    url = {https://github.com/jasenfinch/pdi},
  }