I\'m creating a histogram in R which displays the frequency of several events in a vector. Each event is represented by an integer in the range [1, 9]. I\'m displaying the label
This doesn't sound like a job for a histogram - the event is not a continuous variable. A barplot or dotplot may be more suitable.
Some dummy data
set.seed(123)
vec <- sample(1:9, 100, replace = TRUE)
vec <- factor(vec, labels = paste("My long event name", 1:9))
A barplot is produced via the barplot()
function - we provide it the counts of each event using the table()
function for convenience. Here we need to rotate labels using las = 2
and create some extra space of the labels in the margin
## lots of extra space in the margin for side 1
op <- par(mar = c(10,4,4,2) + 0.1)
barplot(table(vec), las = 2)
par(op) ## reset
A dotplot is produced via function dotchart()
and has the added convenience of sorting out the plot margins for us
dotchart(table(vec))
The dotplot has the advantage over the barplot of using much less ink to display the same information and focuses on the differences in counts across groups rather than the magnitudes of the counts.
Note how I've set the data up as a factor. This allows us to store the event labels as the labels for the factor - thus automating the labelling of the axes in the plots. It also is a natural way of storing data like I understand you to have.