To cite precrec in publications use:

Saito T, Rehmsmeier M (2017). “Precrec: fast and accurate precision-recall and ROC curve calculations in R.” Bioinformatics, 33 (1), 145-147. doi:10.1093/bioinformatics/btw570.

Corresponding BibTeX entry:

  @Article{,
    title = {Precrec: fast and accurate precision-recall and ROC curve
      calculations in R},
    author = {Takaya Saito and Marc Rehmsmeier},
    journal = {Bioinformatics},
    year = {2017},
    volume = {33 (1)},
    pages = {145-147},
    doi = {10.1093/bioinformatics/btw570},
  }