How to create pie charts in R
What are pie charts?
A pie chart is a circular graphical representation that is further subdivided into multiple slices according to the provided numerical values.
How to create a pie chart in R
There are various libraries available in the R programming language to create different types of graphs. We can make a pie chart in R by using the function pie().
pie() function in R
This function accepts positive input values. Various other parameters can be used for this function such as:
colortitleradiuslabels
Syntax
Let’s discuss the basic syntax of creating a pie chart in R:
Pie(x, labels, radius, main, col, clockwise)
Parameters
pie() method in R programming accepts the above arguments as above:
-
x: shows the positive input values for your chart. -
labels: illustrates the heading or description of each slice of your chart. -
radius: shows the radius of the circle regarding your chart. Its value must be between -1 and +1. -
main: This indicates the title of your graph. -
col: is used for showing the color palette. -
clockwise: we must set a value to draw the pie charts’ slices clockwise or anti-clockwise.
Code
The image below is the output generated by these lines of code. It takes states ranking x and labels arguments in the pie() method.
# states rankingsx <- c(40, 30, 60, 21)labels <- c("California", "Washington", "Texas", "Florida")#set name for your filepng(file = "states.png")# call the function to plot the Pie Chartpie(x,labels)
Set colors
To get colors according to each slice, pass the col attribute through the c() method above.
pie(x, labels, col = c("red", "yellow", "green", "blue"))
Code
This method ranks values, state labels, and multiple colors of slices.
x <- c(40,30,60,21)labels <- c("California","Washington","Texas","Florida")# set name for your filepng(file = "states.png")# call the function to plot the Pie Chartpie(x,labels,col=c("red","yellow","green","blue"))
Graph legend
The legend illustrates legend keys or different entities on the plotted area of the graph. We can also create a legend for the pie chart by using the following code.
The legend() method in line 9 generates a legend on the pie chart’s top right corner.
# Data for the graphx <- c(40,30,60,21)labels <- c("California", "Washington", "Texas", "Florida")piepercent <- round(100 * x / sum(x), 1)#set name for your filepng(file = "states.png")# call the function to plot the Pie Chartpie(x, labels = piepercent,main = "Rankings pie chart",col = c("red", "yellow", "green", "blue"))legend("topright",c("California", "Washington", "Texas", "Florida"),cex = 0.8,fill = c("red", "yellow", "green", "blue"))
