Fonts

Problem

You want to use different fonts in your graphs.

Solution

Update: Also see the extrafont package for much better support of fonts for PDF and Windows bitmap output.

Font support in R is generally not very good. It varies between systems, and between output formats.

geom_text

With geom_text or annotate in ggplot2, you can set a number of properties of the text. geom_text is used to add text from the data frame, and annotate is used to add a single text element.

Name Default value
size 5
family "" (sans)
fontface plain
lineheight 1.2
angle 0
hjust 0.5
vjust 0.5

Note that size is in mm, not points.

  1. dat <- data.frame(
  2.     y = 1:3,
  3.     text = c("This is text", "Text with\nmultiple lines", "Some more text")
  4. )
  6. library(ggplot2)
  7. p <- ggplot(dat, aes(x=1, y=y)) + 
  8.        scale_y_continuous(limits=c(0.5, 3.5), breaks=NULL) +
  9.        scale_x_continuous(breaks=NULL)
  11. p + geom_text(aes(label=text))
  13. p + geom_text(aes(label=text), family="Times", fontface="italic", lineheight=.8) +
  14.     annotate(geom="text", x=1, y=1.5, label="Annotation text", colour="red",
  15.              size=7, family="Courier", fontface="bold", angle=30)

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themes and element_text

When controlling elements such as the title, legend, axis labels, and so on, you use element_text, which has the same parameters, except that size is points (not mm), and instead of fontface, it uses face. The default value of size depends on the element; for example, titles are larger than tick labels.

  1. p + geom_point() +
  2.     ggtitle("This is a Title") +
  3.     theme(plot.title=element_text(family="Times", face="bold", size=20))

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Table of fonts

You can use this code to generate a graphical table of fonts. Fonts have short names and canonical family names. You can use either one when specifying the family.

  1. fonttable <- read.table(header=TRUE, sep=",", stringsAsFactors=FALSE,
  2.                         text='
  3. Short,Canonical
  4. mono,Courier
  5. sans,Helvetica
  6. serif,Times
  7. ,AvantGarde
  8. ,Bookman
  9. ,Helvetica-Narrow
  10. ,NewCenturySchoolbook
  11. ,Palatino
  12. ,URWGothic
  13. ,URWBookman
  14. ,NimbusMon
  15. URWHelvetica,NimbusSan
  16. ,NimbusSanCond
  17. ,CenturySch
  18. ,URWPalladio
  19. URWTimes,NimbusRom
  20. ')
  22. fonttable$pos <- 1:nrow(fonttable)
  24. library(reshape2)
  25. fonttable <- melt(fonttable, id.vars="pos", measure.vars=c("Short","Canonical"),
  26.                   variable.name="NameType", value.name="Font")
  28. # Make a table of faces. Make sure factors are ordered correctly
  29. facetable <- data.frame(Face = factor(c("plain","bold","italic","bold.italic"),
  30.                                       levels = c("plain","bold","italic","bold.italic")))
  32. fullfonts <- merge(fonttable, facetable)
  35. library(ggplot2)
  36. pf <- ggplot(fullfonts, aes(x=NameType, y=pos)) + 
  37.              geom_text(aes(label=Font, family=Font, fontface=Face)) +
  38.              facet_wrap(~ Face, ncol=2)

To view it on screen:

  1. pf

What you see on the screen isn’t necessarily the same as what you get when you output to PNG or PDF. To see PNG output:

  1. png('fonttable.png', width=720, height=720, res=72)
  2. print(pf)
  3. dev.off()

Notice that on the system that generated this picture, most of the fonts (at the top) don’t really work. Only the basic fonts (at the bottom) work.

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And PDF output (the image below has been converted from PDF to PNG):

  1. pdf('fonttable.pdf', width=10, height=10)
  2. print(pf)
  3. dev.off()
  5. # Convert to PNG using GraphicsMagick:
  6. # system("gm convert -resize 720x720 -background white fonttable.pdf fonttable-pdf.png")

The PDF device has better font support than the PNG device. All the fonts work (though they’re not necessarily pretty):

PDF font table, converted to PNG