R: Data Analysis and Visualization

Labeling a pie chart with percentage values for each slice

In this recipe, we will learn how to add the percentage values in addition to the names of slices, thus making them more readable.

Getting ready

Once again in this recipe, we will use the browsers.txt example dataset, which contains data about the usage percentage share of different Internet browsers.

How to do it...

First, we will load the browsers.txt dataset and then use the pie() function to draw a pie chart:

browsers<-read.table("browsers.txt",header=TRUE) browsers<-browsers[order(browsers[,2]),] pielabels <- sprintf("%s = %3.1f%s", browsers[,1], 100*browsers[,2]/sum(browsers[,2]), "%") pie(browsers[,2], labels=pielabels, clockwise=TRUE, radius=1, col=brewer.pal(7,"Set1"), border="white", ...