1. rare::data.dtm
    Document-term matrix for adjectives in TripAdvisor hotel reviews
    rda| rds
    dgCMatrix
  2. rare::data.hc
    Hierarchical clustering tree for adjectives in TripAdvisor data set
    rda| rds
    hclust
  3. rare::data.rating
    TripAdvisor hotel review ratings
    json| rda| rds
    integer