R/plotRoc.R

In mikeniemant/nbs: What the Package Does (One Line, Title Case)

#' Plot Receiver Operator Curve
#'
#' @param x Tibble with sensitivity and specificity computed by the performance R package
#' @param group Variable to group coordinates
#' @param title Plot title
#' @param breaks Boolean to plot additional breaks and lines
#' @return A ggplot containing the receiver operator curve
#' @export
plotRoc <- function(x, group = NULL, title = NULL, breaks = F, print_plot) {
  p <- x %>%
    ggplot2::ggplot(ggplot2::aes(x = 1-specificity, y = sensitivity, colour = !!ggplot2::sym(group))) +
    ggplot2::geom_path() +
    ggplot2::geom_abline(slope = 1, intercept = 0, color = "black", linetype = 2) +
    ggplot2::labs(x = "False positive rate (1-specificity)",
                  y = "True positive rate",
                  colour = gsub("(^|[[:space:]])([[:alpha:]])", "\\1\\U\\2",
                                group,
                                perl = TRUE),
                  title = title) +
    ggplot2::scale_x_continuous(limits = c(0, 1),
                                expand = c(0.005, 0.005)) +
    ggplot2::scale_y_continuous(limits = c(0, 1),
                                expand = c(0.005, 0.005)) +
    ggplot2::coord_equal()

  if(breaks) {
    p <- p +
      ggplot2::scale_x_continuous(breaks =  c(0, 0.1, 0.25, 0.5, 0.75, 0.9, 1),
                                  minor_breaks = c(seq(0, 0.1, by = 0.01), seq(0.9, 1, by = 0.01)),
                                  limits = c(0, 1),
                                  expand = c(0.005, 0.005)) +
      ggplot2::scale_y_continuous(breaks = c(0, 0.1, 0.25, 0.5, 0.75, 0.9, 1),
                                  minor_breaks = c(seq(0, 0.1, by = 0.01), seq(0.9, 1, by = 0.01)),
                                  limits = c(0, 1),
                                  expand = c(0.005, 0.005)) +
      ggplot2::coord_equal()
  }

  if(print_plot) {
    print(p)
  } else {
    return(p)
  }
}