Bar Chart in R: How to Create Bar Plot using barplot()

A bar chart depicts data in rectangular bars with a length of the bar proportional to the value of the variable. To create a bar plot in R, you need to use the barplot(height) function, where height is a vector or matrix. Let’s see how to create a bar chart in R using various use cases.

Bar Chart in R

To create a bar chart in R, use the barplot() function. The barplot() function creates a bar plot with vertical or horizontal bars. The barplot() function accepts many arguments and, based on that, it will draw the bar chart.

Syntax

barplot(height, xlab, ylab, main, names.arg, col)

Parameters

height: It is a vector or matrix containing numeric values used in a bar chart.

xlab: It is the label for the x-axis.

ylab: It is the label for the y-axis.

main: It is the title of the bar chart.

names.arg: It is a vector of names appearing under each bar.

col: It is used to give colors to the bars in the graph.

There are lots of other parameters, but you will mostly use these.

Simple barplot Example in R

To create a simple barplot, use the input vector and the name of each bar.

data <- c(11, 18, 19, 21, 46)

barplot(data)

Output

In this example, The height is a vector, or we can say our data, so the values determine the heights of the bars in the plot.

In this bar chart, we have not mentioned any x-label, y-label, main title, color, and other properties. But we can define it. Let’s see how to do that.

Bar Plot Labels, Title, and Colors

To add a title in the bar plot, use the main parameter.

To add the colors in the bar, use the col parameter.

To define an x-axis name, use the xlab and define the y-axis name, use the ylab parameters.

data <- c(11, 18, 19, 21, 46)

barplot(data, main = "Enroll Chart",
        xlab="x-axis", ylab="y-axis",
        col="skyblue")

Output

Create a barplot with two vectors in R

In the above example, we have created a chart based on one vector or height, but now we will define two vectors, one for the x-axis and one for the y-axis, and then create a barplot from those values.

price <- c(580, 1040, 1980, 2810, 3125)
stocks <- c("Happiest", "TechMahindra", "Mindtree", "LTTS", "TCS")

barplot(price, names.arg= stocks, 
        main = "Stocks Pile",col="skyblue"
        xlab = "Stocks Name", ylab = "Stocks Price")

Output

Create a Horizontal barplot from a dataset

R provides many built-in datasets that we can use to create a bar chart. Let’s use the mtcars dataset.

counts <- table(mtcars$gear)
barplot(counts, names.arg=c("3 Gears", "4 Gears", "5 Gears"),
 main="Car Distribution",
 horiz=TRUE, col="skyblue")

Output

Grouped and Stacked Bar Chart in R

The Stacked Bar Chart in R Programming is handy in comparing the data visually. We can create a group bar plot and stack bar plot by using a matrix as input values. More than two variables are represented as a matrix.

Stacked bar plot

counts <- table(mtcars$vs, mtcars$gear)
barplot(counts, main = "Car Distribution Channel",
        xlab = "Number of Gears", col = c("skyblue", "red"),
        legend = rownames(counts))

Output

Grouped Bar Plot in R

counts <- table(mtcars$vs, mtcars$gear)
barplot(counts, main = "Car Distribution Channel",
        xlab = "Number of Gears", col = c("skyblue", "red"),
        legend = rownames(counts), beside = TRUE)

Output

To add a legend in the barplot, pass the legend argument with the values if you specify legend.text = TRUE, legend values are automatically assigned.

That is it for the bar plot in R tutorial.

Krunal Lathiya

Krunal Lathiya is an Information Technology Engineer by education and web developer by profession. He has worked with many back-end platforms, including Node.js, PHP, and Python. In addition, Krunal has excellent knowledge of Data Science and Machine Learning, and he is an expert in R Language. Krunal has written many programming blogs, which showcases his vast expertise in this field.