R/plot.R

In benchr: High Precise Measurement of R Expressions Execution Time

#' @title Plot method for the `benchmark` timings.
#'
#' @description
#' Displays measurement results as a scatter plot, with R expressions on X axis
#' and execution time on Y axis. Each expression is highlighted by its own colour.
#'
#' @param x An object of class `benchmark`.
#' @param units Character. The units to be used in printing the timings.
#' The available units are nanoseconds (`"ns"`), microseconds
#' (`"us"`), milliseconds (`"ms"`), seconds (`"s"`).
#' @param log Logical. Should times be plotted on log scale?
#' @param xlab Character. X axis label.
#' @param ylab Character. Y axis label.
#' @param \dots Not currently used.
#'
#' @details
#' If `ggplot2` package is available, it will be used. In order to switch to default
#' `boxplot` from the `graphics` package set option `benchr.use_ggplot`
#' to `FALSE`: `options(benchr.use_ggplot = FALSE)`.
#'
#' @include utils.R
#' @importFrom graphics plot
#' @method plot benchmark
#' @export
#'
#' @author Artem Klevtsov \email{a.a.klevtsov@gmail.com}
#'
#' @seealso
#' [boxplot.benchmark()]
#'
#' @examples
#' timings <- benchmark(
#'   rchisq(100, 0), rchisq(100, 1), rchisq(100, 2),
#'   rchisq(100, 3), rchisq(100, 5),
#'   times = 1000L
#' )
#' plot(timings)
plot.benchmark <- function(x, units = "auto", log = TRUE, xlab, ylab, ...) {
  x <- convert_units(x, units)
  if (missing(xlab)) {
    xlab <- "Replications"
  }
  if (missing(ylab)) {
    if (log) {
      ylab <- sprintf("Log Execution Time [%s]", attr(x, "units"))
    } else {
      ylab <- sprintf("Execution Time [%s]", attr(x, "units"))
    }
  }
  if (is_installed("ggplot2") && getOption("benchr.use_ggplot", TRUE)) {
    return(plot_ggplot(x, log, xlab, ylab))
  } else {
    plot_default(x, log, xlab, ylab)
  }
  invisible()
}

# ggplot2 variant of the plot
plot_ggplot <- function(x, log = TRUE, xlab, ylab) {
  expr <- as.symbol("expr")
  time <- as.symbol("time")
  aes <- ggplot2::aes(x = seq_along(time), y = time, colour = expr)
  p <- ggplot2::ggplot(x, aes) +
    ggplot2::geom_point(shape = 19) +
    ggplot2::labs(x = xlab, y = ylab, colour = NULL)
  if (log) {
    p <- p + ggplot2::scale_y_log10()
  } else {
    p <- p + ggplot2::expand_limits(y = 0)
  }
  p
}

# graphics variant of the plot
#' @importFrom graphics plot.default legend
plot_default <- function(x, log = TRUE, xlab, ylab) {
  plot.default(x$time,
    col = x$expr, xlab = xlab, ylab = ylab,
    log = ifelse(log, "y", ""), pch = 19
  )
  legend("topright",
    legend = levels(x$expr),
    col = seq_along(levels(x$expr)), pch = 19
  )
}