R/amzn_terms_by_rating.R

In taylorgrant/GSPtext: Tools for scraping and analyzing texts

#' Terms by Average Amazon Rating
#'
#' @description Graph with the most frequent terms used and each term is positioned by the average of all reviews in which that term was used. The dashed line represents the average star rating for the product.
#'
#' For example, if reviewers for a specific product used the word "perfect" 88 times and the average rating of the reviews using that term is 4.85,
#' "perfect" will be plotted at (x = 88, y = 4.85).
#'
#'
#' @param data Data frame created by `GSPtext::get_reviews()` or in the same format
#'
#' @return ggplot2 graph - scatterplot with overlaid text
#' @export
#'
#' @examples
#' \dontrun{
#' amzn_terms_by_rating(data),
#'
#' # to save after running
#' amzn_terms_by_rating(data)
#' ggsave("directory/filename.png")}
amzn_terms_by_rating <- function(data) {

  # get brand/product from link
  bp <- gsub("\\/.*", "", urltools::url_parse(data$link[1])$path)

  data %>%
    dplyr::mutate(text = gsub("[[:punct:]]|[[:digit:]]", "", text)) %>%
    tidytext::unnest_tokens(word, text) %>%
    dplyr::anti_join(tidytext::stop_words) %>%
    dplyr::group_by(word) %>%
    dplyr::summarise(
      n = dplyr::n(),
      rating = mean(stars)
    ) %>%
    ggplot2::ggplot(ggplot2::aes(n, rating)) +
    ggplot2::geom_hline(
      yintercept = mean(data$stars), lty = 2,
      color = "gray50", size = 1
    ) +
    ggplot2::geom_jitter(color = "midnightblue", alpha = 0.4, size = .5) +
    ggplot2::geom_text(ggplot2::aes(label = word),
              check_overlap = TRUE,
              vjust = "top", hjust = "left", size = 3
    ) +
    ggplot2::scale_x_log10() +
    ggplot2::theme_minimal() +
    ggplot2::theme(panel.grid = ggplot2::element_blank(),
                   axis.line = ggplot2::element_line(colour = "darkgray",
                                                     size = .2)) +
    ggplot2::labs(x = "Term Count", y = "Star Rating",
         title = "Most common terms used in reviews, by average star rating of each term",
         subtitle = glue::glue("{bp}"),
         caption = glue::glue("Analysis by GS&P; Source: Amazon\ \n Dashed line represents averaage star rating for this product: {round(mean(data$stars), 2)} average.\nBased on {dim(data)[1]} reviews")
    )
}