Creating plots using the xkcd package in R

xkcd styled graphs using the xkcd package in R. Steps done on R version 3.0.1 (2013-05-16) and on Windows, i386-w64-mingw32/i386 (32-bit). Steps followed are from the xkcd-intro.pdf file i.e. the xkcd vignette.

install.packages("xkcd")
library(xkcd)
library(extrafont)
library(ggplot2)

#do you have xkcd fonts?
if( "xkcd" %in% fonts()) {
   p <- ggplot() + geom_point(aes(x=mpg, y=wt), data=mtcars) +
   theme(text = element_text(size = 16, family = "xkcd"))
} else {
   warning("Not xkcd fonts installed!")
   p <- ggplot() + geom_point(aes(x=mpg, y=wt), data=mtcars)
}
#Warning message:
#Not xkcd fonts installed!

#download the font and install it
#http://simonsoftware.se/other/xkcd.ttf
#then import all fonts
font_import()
#load all fonts
loadfonts()
#Despite loading all fonts
#I had to restart R to get the fonts loaded properly

#opens the xkcd-intro.pdf
vignette("xkcd-intro")

xrange <- range(mtcars$mpg)
yrange <- range(mtcars$wt)
set.seed(123) # for reproducibility
p <- ggplot() + geom_point(aes(mpg, wt), data=mtcars) + xkcdaxis(xrange,yrange)
p

Cartoon characters

To include cartoon characters in the graph, use the xkcdman() function.

ratioxy <- diff(xrange)/diff(yrange)
mapping <- aes(x, y, scale, ratioxy, angleofspine ,anglerighthumerus, anglelefthumerus, anglerightradius, angleleftradius, anglerightleg, angleleftleg, angleofneck, linetype=city)
dataman <- data.frame(x= c(15,30), y=c(3, 4), scale = c(0.3,0.51), ratioxy = ratioxy, angleofspine = -pi/2, anglerighthumerus = c(pi/4, -pi/6), anglelefthumerus = c(pi/2 + pi/4, pi +pi/6), anglerightradius = c(pi/3, -pi/3), angleleftradius = c(pi/3, -pi/3), anglerightleg = 3*pi/2 - pi / 12, angleleftleg = 3*pi/2 + pi / 12, angleofneck = runif(1, 3*pi/2-pi/10, 3*pi/2+pi/10), city=c("Liliput","Brobdingnag"))
q <- ggplot() + geom_point(aes(mpg, wt, colour=as.character(vs)), data=mtcars) + xkcdaxis(xrange,yrange) + xkcdman(mapping, dataman)

Scatterplot

volunteers <- data.frame(year=c(2007:2011), number=c(56470, 56998, 59686, 61783, 64251))
xrange <- range(volunteers$year)
yrange <- range(volunteers$number)
ratioxy <- diff(xrange) / diff(yrange)
datalines <- data.frame(xbegin=c(2008.3,2010.5),ybegin=c(63000,59600), xend=c(2008.5,2010.3), yend=c(63400,59000))
p <- ggplot() + geom_smooth(mapping=aes(x=year, y =number), data =volunteers, method="loess") + xkcdaxis(xrange,yrange) + ylab("Volunteers at Caritas Spain")
p

Bar charts

data <- data.frame(year=c(2007:2011), number=c(56470, 56998, 59686, 61783, 64251))
data$xmin <- data$year - 0.1
data$xmax <- data$year + 0.1
data$ymin <- 50000
data$ymax <- data$number
xrange <- range(min(data$xmin)-0.1, max(data$xmax) + 0.1)
yrange <- range(min(data$ymin)+500, max(data$ymax) + 1000)
mapping <- aes(xmin=xmin,ymin=ymin,xmax=xmax,ymax=ymax)
p <- ggplot() + xkcdrect(mapping,data) + xkcdaxis(xrange,yrange) + xlab("Year") + ylab("Volunteers at Caritas Spain")
p

Barchart of piRNA lengths from NONCODE

Previously I had used the SeqinR package in R to get the length distribution of all human piRNAs in the NONCODE database. Here a produce a xkcd styled bar chart of the piRNA lengths.

data <- data.frame(size = c(26,27,28,29,30,31,32), freq = c(3552, 3540, 4127, 7166, 8216, 4410, 1141))
data
  size freq
1   26 3552
2   27 3540
3   28 4127
4   29 7166
5   30 8216
6   31 4410
7   32 1141

data$xmin <- data$size - 0.1
data$xmax <- data$size + 0.1
data$ymin <- 0
data$ymax <- data$freq
xrange <- range(min(data$xmin)-0.1, max(data$xmax) + 0.1)
yrange <- range(min(data$ymin)+500, max(data$ymax) + 1000)
mapping <- aes(xmin=xmin,ymin=ymin,xmax=xmax,ymax=ymax)
p <- ggplot() + xkcdrect(mapping,data) + xkcdaxis(xrange,yrange) + xlab("piRNA size") + ylab("Frequency")
p

See more

More information on the xkcd package in R