R/mod_popExp_fct_boxplot.R

In Biogen-Inc/tidyCDISC: Quick Table Generation & Exploratory Analyses on ADaM-Ish Datasets

#' Boxplot
#' 
#' Create boxplot using either the selected response variable
#' or if a PARAMCD is selected, then plot the corresponding value
#' and filter the data by week
#' 
#' @param data Merged data to be used in plot
#' @param yvar Selected y-axis 
#' @param group Selected x-axis 
#' @param value If yvar is a PARAMCD then the user must select 
#' AVAL, CHG, or BASE to be plotted on the y-axis
#' @param points \code{logical} whether to add a jitter to the plot
#' 
#' @family popExp Functions
#' @keywords popEx
#' 
#' @return A ggplot object representing the boxplot
#' 
#' @noRd
app_boxplot <- function(data, yvar, group, value = NULL, points = FALSE) {
  
  # BDS Parameter not selected
  if (yvar %in% colnames(data)) {
    
    # initialize plot
    p <- ggplot2::ggplot(data) + 
      ggplot2::aes_string(x = group, y = yvar) +
      ggplot2::ylab(best_lab(data, yvar))
    
    # initialize title with variable of interst
    var_title <- paste(best_lab(data, yvar), "by", best_lab(data, group))
    
  # BDS Param selected
  } else {
    # Filter data on PARAMCD
    d <- data %>% dplyr::filter(PARAMCD == yvar)
    
    # Initialize title with variable selected
    var_label <- paste(unique(d$PARAM))
    var_title <- paste(var_label, "by", best_lab(data, group))
    
    # Initialize plot
    p <- d %>%
      ggplot2::ggplot() +
      ggplot2::aes_string(x = group, y = value) +
      ggplot2::ylab(glue::glue("{var_label} ({best_lab(data, value)})"))
  }
  
  # Add layer of common plot elements
  p <- p + 
    ggplot2::geom_boxplot() +
    ggplot2::xlab("") +
    ggplot2::theme_bw() +
    ggplot2::theme(text = ggplot2::element_text(size = 12),
                   axis.text = ggplot2::element_text(size = 12),
                   plot.title = ggplot2::element_text(size = 16)) +
    ggplot2::ggtitle(var_title)
  
  # Conditionally add jittered points to plot
  if (points) { p <- p + ggplot2::geom_jitter() }
  
  return(p)
}