R/bundestag.R

In clauswilke/dviz.supp: Supporting materials for Claus Wilke's data visualization book

#' Composition of the 8th German Bundestag
#' 
#' Composition of the 8th Bundestag, from 1976-1980. The `party` and `seat` columns should be self-explanatory.
#' The `colors_original` column holds the traditional colors used to represent these parties, and the `colors`
#' column holds a variation of these colors that are less saturated.
#' 
#' @references
#' Source: \url{https://en.wikipedia.org/wiki/Bundestag#Distribution_of_seats_in_the_Bundestag}
#' 
#' @examples
#' library(dplyr)
#' library(ggplot2)
#' library(ggforce)
#' 
#' # calculate the start and end angles for each pie
#' bund_pie <- bundestag %>%
#'   arrange(seats) %>%
#'   mutate(seat_total = sum(seats),
#'          end_angle = 2*pi*cumsum(seats)/seat_total,   # ending angle for each pie slice
#'          start_angle = lag(end_angle, default = 0),   # starting angle for each pie slice
#'          mid_angle = 0.5*(start_angle + end_angle),   # middle of each pie slice, for the text label
#'          hjust = ifelse(mid_angle>pi, 1, 0),
#'          vjust = ifelse(mid_angle<pi/2 | mid_angle>3*pi/2, 0, 1))
#' 
#' rpie = 1
#' rlabel = 1.05 * rpie
#' 
#' ggplot(bund_pie) + 
#'   geom_arc_bar(aes(x0 = 0, y0 = 0, r0 = 0, r = rpie,
#'                    start = start_angle, end = end_angle, fill = party)) +
#'   geom_text(aes(x = rlabel*sin(mid_angle), y = rlabel*cos(mid_angle), label = party,
#'                 hjust = hjust, vjust = vjust)) +
#'   coord_fixed() +
#'   scale_x_continuous(limits = c(-1.6, 1.3), name = "", breaks = NULL, labels = NULL) +
#'   scale_y_continuous(limits = c(-1.1, 1.3), name = "", breaks = NULL, labels = NULL) +
#'   scale_fill_manual(values = bund_pie$colors[order(bund_pie$party)]) +
#'   guides(fill = "none") +
#'   theme_nothing()
"bundestag"