How can we make xkcd style graphs?

Question

Apparently, folk have figured out how to make xkcd style graphs in Mathematica and in LaTeX. Can we do it in R? Ggplot2-ers? A geom_xkcd and/or theme_xkcd?

I guess i

Answer 1

Basic line-drawing function:

xkcd_line <- function(x, y, color) {
  len <- length(x);
  rg <- par("usr");
  yjitter <- (rg[4] - rg[3]) / 1000;
  xjitter <- (rg[2] - rg[1]) / 1000;
  x_mod <- x + rnorm(len) * xjitter;
  y_mod <- y + rnorm(len) * yjitter;
  lines(x_mod, y_mod, col='white', lwd=10);
  lines(x_mod, y_mod, col=color, lwd=5);
}

Basic axis:

xkcd_axis <- function() {
  rg <- par("usr");
  yaxis <- 1:100 / 100 * (rg[4] - rg[3]) + rg[3];
  xaxis <- 1:100 / 100 * (rg[2] - rg[1]) + rg[1];
  xkcd_line(1:100 * 0 + rg[1] + (rg[2]-rg[1])/100, yaxis,'black')
  xkcd_line(xaxis, 1:100 * 0 + rg[3] + (rg[4]-rg[3])/100, 'black')
}

And sample code:

data <- data.frame(x=1:100)
data$one <- exp(-((data$x - 50)/10)^2)
data$two <- sin(data$x/10)
plot.new()
plot.window(
    c(min(data$x),max(data$x)),
    c(min(c(data$one,data$two)),max(c(data$one,data$two))))
xkcd_axis()
xkcd_line(data$x, data$one, 'red')
xkcd_line(data$x, data$two, 'blue')

Produces: