gapminder: Data from Gapminder

#' Gapminder color schemes.
#' 
#' Color schemes for the countries and continents in the Gapminder data.
#' 
#' @aliases continent_colors
#' @format Named character vectors giving country and continent colors:
#' \describe{ 
#'   \item{country_colors}{colors for the 142 countries}
#'   \item{continent_colors}{colors for the 5 continents}
#'   }
#' @seealso \code{\link{gapminder}} for a description of the dataset
#' @examples
#' # ggplot2 examples are below these base graphics examples!
#' 
#' # using country_colors with base graphics
#' 
#' # for convenience, integrate the country colors into the data.frame
#' gap_with_colors <-
#'   data.frame(gapminder,
#'              cc = I(country_colors[match(gapminder$country,
#'                                          names(country_colors))]))
#'
#' # bubble plot, focus just on Africa and Europe in 2007
#' keepers <- with(gap_with_colors,
#'                 continent %in% c("Africa", "Europe") & year == 2007)
#' plot(lifeExp ~ gdpPercap, gap_with_colors,
#'      subset = keepers, log = "x", pch = 21,
#'      cex = sqrt(gap_with_colors$pop[keepers]/pi)/1500,
#'      bg = gap_with_colors$cc[keepers])
#' 
#' if (require(ggplot2)) {
#' 
#' # with ggplot2, just provide country_colors to scale_color_manual():
#' # ... + scale_color_manual(values = country_colors) + ...
#' 
#' # simple line plot for 5 countries
#' h_countries <- c("Egypt", "Haiti", "Romania", "Thailand", "Venezuela")
#' h_dat <- droplevels(subset(gapminder, country %in% h_countries))
#' h_dat$country <- with(h_dat, reorder(country, lifeExp, max))
#' ggplot(h_dat, aes(x = year, y = lifeExp)) +
#'   geom_line(aes(color = country)) +
#'   scale_colour_manual(values = country_colors) +
#'   guides(color = guide_legend(reverse = TRUE))
#' 
#' # spaghetti plot for lots of countries
#' ggplot(subset(gapminder, continent != "Oceania"),
#'        aes(x = year, y = lifeExp, group = country, color = country)) +
#'   geom_line(lwd = 1, show_guide = FALSE) + facet_wrap(~ continent) +
#'   scale_color_manual(values = country_colors) +
#'   theme_bw() + theme(strip.text = element_text(size = rel(1.1)))
#'   
#' # bubble plot for lots of countries
#' gap_bit <- subset(gapminder, year == 2007 & continent != "Oceania")
#' gap_bit <- gap_bit[with(gap_bit, order(continent, -1 * pop)), ]
#' ggplot(gap_bit, aes(x = gdpPercap, y = lifeExp, size = pop)) +
#'   scale_x_log10(limits = c(150, 115000)) + ylim(c(16, 96)) +
#'   geom_point(pch = 21, color = 'grey20', show_guide = FALSE) +
#'   scale_size_area(max_size = 40) +
#'   facet_wrap(~ continent) + coord_fixed(ratio = 1/43) +
#'   aes(fill = country) + scale_fill_manual(values = country_colors) +
#'   theme_bw() + theme(strip.text = element_text(size = rel(1.1)))
#' }
#'
"country_colors"