To cite TrajectoryGeometry in publications use:

  Anna Laddach and Michael Shapiro, TrajectoryGeometry: an R package
  for discovering directional change in gene expression,
  https://github.com/AnnaLaddach/TrajectoryGeometry

A BibTeX entry for LaTeX users is

  @Misc{,
    title = {TrajectoryGeometry},
    author = {Anna Laddach and Michael Shapiro},
    year = {2020},
    url = {https://github.com/AnnaLaddach/TrajectoryGeometry},
  }