{"id":1663,"date":"2014-01-12T21:46:35","date_gmt":"2014-01-13T02:46:35","guid":{"rendered":"http:\/\/lukemiller.org\/?p=1663"},"modified":"2014-01-12T21:46:35","modified_gmt":"2014-01-13T02:46:35","slug":"part-2-make-your-r-figures-legible-in-powerpointkeynote-presentations","status":"publish","type":"post","link":"https:\/\/lukemiller.org\/index.php\/2014\/01\/part-2-make-your-r-figures-legible-in-powerpointkeynote-presentations\/","title":{"rendered":"Part 2: Make your R figures legible in Powerpoint\/Keynote presentations"},"content":{"rendered":"

In the previous post<\/a>, I outlined some tips for increasing the size of figure labels for figures that are meant to be displayed on a projector. The previous post used the base R plot()<\/code> function, but the procedure when plotting with ggplot2<\/a> is different and usually quite a bit simpler than the stock R plotting functions. As before, I’m outputting the figures here as 1024×768 PNG image files, since they’re sure to work in whatever version of PowerPoint or Keynote you’re stuck using. <\/p>\n

I’ll begin by generating some random data and dates to use in the plots. Since ggplot2 is an add-on package, it also needs be loaded by R before plotting.
\n[code lang=”r”]
\ndf = data.frame(x = rnorm(30), y = runif(30,min = 10,max = 10000),
\n\t\tdates = seq(as.Date(‘2013-12-01’),(as.Date(‘2013-12-01’)+29), by = 1))
\n# load libraries
\nrequire(ggplot2)
\n[\/code]<\/p>\n

To output a PNG file, you start by calling the png()<\/code> function and feeding it some arguments to lay out the size of the output figure. Follow that with your ggplot2 commands, then a print()<\/code> to print the figure to disk, and finish with dev.off()<\/code> to save the file. <\/p>\n

[code lang=”r”]
\npng(file = "pngtest9.png", width = 1024, height = 768, units = ‘px’)
\n# lay out basic figure
\nmygraph = ggplot(data = df, aes(x = dates, y = y))
\nmygraph = mygraph + geom_point()
\nprint(mygraph)
\ndev.off() # close plot and save to disk
\n[\/code]
\n

\"The<\/a>
The basic plot in a png file. All the labels are tiny.<\/figcaption><\/figure><\/p>\n

We ought to add some axis labels to the existing graph<\/code> object:
\n[code lang=”r”]
\nmygraph = mygraph + xlab("Sample dates, 2013")
\nmygraph = mygraph + ylab("Some response variable")
\npng(file = "pngtest10.png", width = 1024, height = 768, units = ‘px’)
\nprint(mygraph)
\ndev.off()
\n[\/code]
\n

\"The<\/a>
The plot with some more descriptive axis titles. Still too small to read.<\/figcaption><\/figure><\/p>\n

The default font sizes in the output figure are far too small to read on a projector. To correct this, you can quickly modify the existing graph<\/code> object to inflate the label sizes. The built-in formatting in ggplot2 makes this procedure much simpler than in the standard plot()<\/code> function, since ggplot2 shoves the margins around to make things fit nicely for you. The size = rel(2)<\/code> argument increases the labels to 2x the default size.
\n[code lang=”r”]
\n# Increase size of all axis labels
\nmygraph = mygraph + theme(axis.text = element_text(size = rel(2)))
\nmygraph = mygraph + theme(axis.title = element_text(size = rel(2)))
\npng(file = "pngtest11.png", width = 1024, height = 768, units = ‘px’)
\nprint(mygraph)
\ndev.off()
\n[\/code]
\n

\"Now<\/a>
Now the axis labels are large enough to read, but they could probably be larger.<\/figcaption><\/figure><\/p>\n

With large labels on the x-axis like this, if you want to print them any larger it becomes necessary to rotate them to squeeze a decent number of labels in. Thankfully this is simple to do in ggplot2.
\n[code lang=”r”]
\n# Rotate x axis tick labels and increase size even further
\nmygraph = mygraph + theme(axis.text.x = element_text(angle = 45, vjust = 0.9,
\n\t\t\t\thjust = 0.9, size = rel(3)))
\npng(file = "pngtest12.png", width = 1024, height = 768, units = ‘px’)
\nprint(mygraph)
\ndev.off()
\n[\/code]
\n

\"Now<\/a>
Now it’s just getting silly, but here are some large x-axis labels.<\/figcaption><\/figure><\/p>\n","protected":false},"excerpt":{"rendered":"

In the previous post, I outlined some tips for increasing the size of figure labels for figures that are meant to be displayed on a projector. The previous post used the base R plot() function, but the procedure when plotting with ggplot2 is different and usually quite a bit simpler than the stock R plotting […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[218],"tags":[91,175,17,174],"class_list":["post-1663","post","type-post","status-publish","format-standard","hentry","category-r-project","tag-ggplot2","tag-keynote","tag-plotting","tag-powerpoint"],"_links":{"self":[{"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/posts\/1663","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/comments?post=1663"}],"version-history":[{"count":8,"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/posts\/1663\/revisions"}],"predecessor-version":[{"id":1675,"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/posts\/1663\/revisions\/1675"}],"wp:attachment":[{"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/media?parent=1663"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/categories?post=1663"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lukemiller.org\/index.php\/wp-json\/wp\/v2\/tags?post=1663"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}