R/asymmetrise_stats.R

In ggasym: Asymmetric Matrix Plotting in 'ggplot2'

#' Prepare an asymmetric data table from a statistical test
#'
#' @description This function prepares the results of a statistical test for
#'   plotting using `geom_asymmat` from the ggasym package. For more
#'   information, see \code{vignette(ggasym-stats)}
#'
#' @param df either the results of a statistical test or the tidy tibble from
#'   using the \code{broom::tidy()} function
#' @param contrast_sep the separation used between the names being compared; it
#'   is usually a hyphen (set as default here); since it is passed as the
#'   \code{pattern} parameter to \code{stringr::str_split_fixed()}, this can be
#'   any regular expression that will reliably split the \code{"contrast"} (or
#'   \code{"comparison"} in 'broom' version <0.70) column returned by
#'   \code{broom::tidy()}.
#'
#' @return a tibble object that can be used as direct input for 'ggplot2' for
#'   use  with the \code{geom_asymmat} geom
#'
#' @importFrom rlang enquo !! :=
#' @importFrom magrittr %>%
#' @export asymmetrise_stats
asymmetrise_stats <- function(df, contrast_sep = "-") {
  df <- prepare_data(df)

  # Remove the code for version 0.5.6 of 'broom' when 0.7.0 has been out
  # for awhile. This comment was left on May 29, 2020. The code can likely be
  # removed 6 months from now. Also remove the "comparison" at the bottom
  # of this file.
  if (utils::packageVersion("broom") > 0.6) {
    new_df <- df %>%
      dplyr::mutate(
        x = stringr::str_split_fixed(
          contrast,
          contrast_sep, 2
        )[, 1],
        y = stringr::str_split_fixed(
          contrast,
          contrast_sep, 2
        )[, 2]
      )
  } else {
    new_df <- df %>%
      dplyr::mutate(
        x = stringr::str_split_fixed(
          comparison,
          contrast_sep, 2
        )[, 1],
        y = stringr::str_split_fixed(
          comparison,
          contrast_sep, 2
        )[, 2]
      )
  }

  new_df <- dplyr::bind_rows(new_df, swap_cols(new_df, x, y))
  return(asymmetrise(new_df, x, y))
}


#' @rdname asymmetrise_stats
#' @export asymmetrize_stats
asymmetrize_stats <- asymmetrise_stats


#' Prepares the input data into asymmetrise_stats
#'
#' @description Tries to make the data ready for use in the
#'     \code{asymmetrise_stats()} function using \code{broom::tidy()}
#'
#' @param df input data of either a \code{tibble}, \code{data.frame}, or results from a
#'     statistical test
#'
#' @return a \code{tibble} data table
#'
#' @section Warning:
#'     If you repeatedly get errors, try preparing the data before-hand using
#'     \code{broom::tidy(df)}
#'
#' @examples
#' a <- rnorm(10, mean = 1, sd = 1)
#' b <- rnorm(10, mean = 1.5, sd = 1)
#' prepare_data(t.test(a, b))
#' @export prepare_data
prepare_data <- function(df) {
  if (is.data.frame(df) | tibble::is_tibble(df)) {
    return(df)
  } else {
    new_df <- tryCatch(
      broom::tidy(df),
      error = function(x) {
        stop("Could not handle input data; try turning into a tibble using the broom package")
      }
    )

    if (tibble::is_tibble(new_df)) {
      return(new_df)
    } else {
      stop("Unable to parse data")
    }
  }
}


# for "asymmetrise_stats"
utils::globalVariables(c("contrast", "comparison", "x", "y"), add = TRUE)