Sparklines are small and simple line graphs, useful to summarize trend data in a small space. The word sparklines was coined by Prof. Edward Tufte. In this recipe, we will learn how to make sparklines using a basic plot()
function.
We will use the base graphics library for this recipe, so all you need to do is run the recipe at the R prompt. It is good practice to save your code as a script for use again later.
Let's represent our city rainfall data in the form of sparklines:
rain <- read.csv("cityrain.csv") par(mfrow=c(4,1),mar=c(5,7,4,2),omi=c(0.2,2,0.2,2)) for(i in 2:5) { plot(rain[,i],ann=FALSE,axes=FALSE,type="l", col="gray",lwd=2) mtext(side=2,at=mean(rain[,i]),names(rain[i]), las=2,col="black") mtext(side=4,at=mean(rain[,i]),mean(rain[i]), las=2,col="black") points(which.min(rain[,i]),min(rain[,i]),pch=19,col="blue") points(which.max(rain[,i]),max(rain[,i]),pch=19,col="red") }