stat_bin_step

stat_bin_step <- function(mapping = NULL, data = NULL,
                     geom = "step", position = "stack",
                     ...,
                     binwidth = NULL,
                     bins = NULL,
                     center = NULL,
                     boundary = NULL,
                     breaks = NULL,
                     closed = c("right", "left"),
                     pad = FALSE,
                     na.rm = FALSE,
                     show.legend = NA,
                     inherit.aes = TRUE) {

  layer(
    data = data,
    mapping = mapping,
    stat = StatBinStep,
    geom = geom,
    position = position,
    show.legend = show.legend,
    inherit.aes = inherit.aes,
    params = list(
      binwidth = binwidth,
      bins = bins,
      center = center,
      boundary = boundary,
      breaks = breaks,
      closed = closed,
      pad = pad,
      na.rm = na.rm,
      ...
    )
  )
}

StatBinStep <- ggproto("StatBinStep", StatBin,
  compute_group = function(data, scales, binwidth = NULL, bins = NULL,
                           center = NULL, boundary = NULL,
                           closed = c("right", "left"),
                           breaks = NULL,
                           # The following arguments are not used, but must
                           # be listed so parameters are computed correctly
                           origin = NULL, right = NULL, drop = NULL,
                           width = NULL) {
    pad <- TRUE
    if (!is.null(breaks)) {
      if (!scales$x$is_discrete()){
         breaks <- scales$x$transform(breaks)
      }
      bins <- bin_breaks(breaks, closed)
    } else if (!is.null(binwidth)) {
      if (is.function(binwidth)) {
        binwidth <- binwidth(data$x)
      }
      bins <- bin_breaks_width(scales$x$dimension(), binwidth,
        center = center, boundary = boundary, closed = closed)
    } else {
      bins <- ggplot2:::bin_breaks_bins(scales$x$dimension(), bins, center = center,
        boundary = boundary, closed = closed)
    }
    out <- ggplot2:::bin_vector(data$x, bins, weight = data$weight, pad = pad)
    out <- transform(out,
                    x = xmin,
                    y = density)
    out
  }
)