Faceting for subplots in R Programming - Mini Project: Build & Apply

Faceting for Subplots in R with ggplot2

📖 Scenario: You are a data analyst working with a dataset of car models and their fuel efficiency. You want to create separate plots for each car manufacturer to compare their fuel efficiency visually.

🎯 Goal: Build a faceted plot using ggplot2 in R that shows fuel efficiency for different car models, separated by manufacturer in subplots.

📋 What You'll Learn

Create a data frame called cars with columns manufacturer, model, and mpg with exact values

Create a ggplot object called p with model on x-axis and mpg on y-axis

Add points to the plot using geom_point()

Use facet_wrap() to create subplots by manufacturer

Print the plot object p

💡 Why This Matters

🌍 Real World

Faceting helps compare groups side-by-side in separate plots, useful in data analysis and reporting.

💼 Career

Data analysts and scientists use faceting to explore and present data clearly across categories.

1

Create the data frame

Create a data frame called cars with these exact columns and values:
manufacturer: 'Ford', 'Ford', 'Toyota', 'Toyota', 'Honda', 'Honda'
model: 'F-150', 'Mustang', 'Corolla', 'Camry', 'Civic', 'Accord'
mpg: 20, 25, 30, 28, 32, 31

R Programming

# Create the data frame cars with manufacturer, model, and mpg columns
# Your code here

Need a hint?

Use data.frame() with vectors for each column named exactly manufacturer, model, and mpg.

2

Load ggplot2 library

Load the ggplot2 library by writing library(ggplot2)

R Programming

cars <- data.frame(
  manufacturer = c('Ford', 'Ford', 'Toyota', 'Toyota', 'Honda', 'Honda'),
  model = c('F-150', 'Mustang', 'Corolla', 'Camry', 'Civic', 'Accord'),
  mpg = c(20, 25, 30, 28, 32, 31)
)
# Load the ggplot2 library
# Your code here

Need a hint?

Type library(ggplot2) to load the plotting package.

3

Create the faceted plot

Create a ggplot object called p using cars data, mapping model to x-axis and mpg to y-axis, add points with geom_point(), and use facet_wrap(~manufacturer) to create subplots by manufacturer

R Programming

cars <- data.frame(
  manufacturer = c('Ford', 'Ford', 'Toyota', 'Toyota', 'Honda', 'Honda'),
  model = c('F-150', 'Mustang', 'Corolla', 'Camry', 'Civic', 'Accord'),
  mpg = c(20, 25, 30, 28, 32, 31)
)
library(ggplot2)

# Create the ggplot object p with points and facet_wrap by manufacturer
# Your code here

Need a hint?

Use ggplot() with aes(x = model, y = mpg), add geom_point(), then add facet_wrap(~manufacturer).

4

Display the faceted plot

Print the plot object p using print(p)

R Programming

cars <- data.frame(
  manufacturer = c('Ford', 'Ford', 'Toyota', 'Toyota', 'Honda', 'Honda'),
  model = c('F-150', 'Mustang', 'Corolla', 'Camry', 'Civic', 'Accord'),
  mpg = c(20, 25, 30, 28, 32, 31)
)
library(ggplot2)

p <- ggplot(cars, aes(x = model, y = mpg)) +
  geom_point() +
  facet_wrap(~manufacturer)

# Print the plot p
# Your code here

Need a hint?

Use print(p) to display the plot.