tikz image As x-axis

tikz_image_x_axis.R

## flags borrowed from 
## http://flagpedia.net/

## use LaTeX tikzDevice to render images as x-axis labels
## based on baptiste: https://gist.github.com/baptiste/9505ff4f54b31d1d7149e435faf295f9

library(tikzDevice)
library(ggplot2)
options(tikzLatexPackages = c(getOption("tikzLatexPackages"), "\\usepackage{graphicx}\n"))

d <- data.frame(x = 1:10, y = 1:10)
p <- qplot(x, y, data = d) + 
  theme_bw() + 
  labs(x = "") +
  theme(axis.text.x = element_text(size = 12 * 0.8, 
                                   lineheight = 0.9, 
                                   vjust = -5)) +
  scale_x_continuous(breaks = c(2, 5, 8),
                     labels = c("\\includegraphics[scale=0.1]{us.png}",
                                "\\includegraphics[scale=0.1]{fr.png}",
                                "\\includegraphics[scale=0.1]{au.png}"))

tikz("xaxis.tex", standAlone = TRUE, width = 4, height = 4)
print(p)
dev.off()
tools::texi2dvi("xaxis.tex", pdf = TRUE)