CODEWITHSUNDEEP
rhistogram
Wakan Tanka
Wakan Tanka

Reputation: 8052

Rotate labels for histogram bars - shown via: labels = TRUE

Here is shown how to label histogram bars with data values or percents using labels = TRUE. Is it also possible to rotate those labels? My goal is to rotate them to 90 degrees because now the labels over bars overrides each other and it is unreadable.

PS: please note that my goal is not to rotate y-axis labels as it is shown e.g. here

Upvotes: 0

Views: 2653

Answers (1)

r2evans
r2evans

Reputation: 160677

Using mtcars, here's one brute-force solution (though it isn't very brutish):

h <- hist(mtcars$mpg)
maxh <- max(h$counts)
strh <- strheight('W')
strw <- strwidth(max(h$counts))
hist(mtcars$mpg, ylim=c(0, maxh + strh + strw))
text(h$mids, strh + h$counts, labels=h$counts, adj=c(0, 0.5), srt=90)

The srt=90 is the key here, rotating 90 degrees counter-clockwise (anti-clockwise?).

maxh, strh, and strw are used (1) to determine how much to extend the y-axis so that the text is not clipped to the visible figure, and (2) to provide a small pad between the bar and the start of the rotated text. (The first reason could be mitigated by xpd=TRUE instead, but it might impinge on the main title, and will be a factor if you set the top margin to 0.)

enter image description here

Note: if using density instead of frequency, you should use h$density instead of h$counts.

Edit: changed adj, I always forget the x/y axes on it stay relative to the text regardless of rotation.

Edit #2: changing the first call to hist so the string height/width are calculate-able. Unfortunately, plotting twice is required in order to know the actual height/width.

Upvotes: 3

Related Questions