Histogram and density plots in R Programming - Mini Project: Build & Apply

Histogram and Density Plots

📖 Scenario: You are a data analyst working with a small dataset of daily temperatures. You want to understand how the temperatures are distributed by creating a histogram and a density plot.

🎯 Goal: Build an R script that creates a vector of temperature data, sets a bin width for the histogram, generates both a histogram and a density plot using base R plotting functions, and then displays the plots.

📋 What You'll Learn

Create a numeric vector called temperatures with the exact values: 22, 25, 19, 24, 30, 28, 21, 23, 27, 26

Create a numeric variable called bin_width and set it to 3

Use the hist() function with breaks=seq() to create a histogram of temperatures with bins of width bin_width

Use the plot() function with density() to create a density plot of temperatures

Print both plots so they are visible

💡 Why This Matters

🌍 Real World

Histograms and density plots help you understand how data points are spread out, which is useful in weather analysis, sales data, or any measurements.

💼 Career

Data analysts and scientists use these plots to explore data distributions before making decisions or building models.

1

Create the temperature data vector

Create a numeric vector called temperatures with these exact values: 22, 25, 19, 24, 30, 28, 21, 23, 27, 26

R Programming

# Create the temperatures vector with the exact values
# Your code here

Need a hint?

Use the c() function to combine numbers into a vector.

2

Set the bin width for the histogram

Create a numeric variable called bin_width and set it to 3

R Programming

temperatures <- c(22, 25, 19, 24, 30, 28, 21, 23, 27, 26)
# Create bin_width variable and set it to 3
# Your code here

Need a hint?

Just assign the number 3 to the variable bin_width.

3

Create the histogram and density plot

Use the hist() function with breaks=seq() to create a histogram of temperatures with bins of width bin_width. Then use the plot() function with density() to create a density plot of temperatures.

R Programming

temperatures <- c(22, 25, 19, 24, 30, 28, 21, 23, 27, 26)
bin_width <- 3
# Create histogram with breaks using seq from min to max with bin_width
# Create density plot using plot and density functions
# Your code here

Need a hint?

Use seq(min(temperatures), max(temperatures) + bin_width, by=bin_width) to create breaks for the histogram bins.

Use density() to calculate density and plot() to draw it.

4

Display the plots

Run the code so that both the histogram and the density plot are displayed in the R plotting window.

R Programming

temperatures <- c(22, 25, 19, 24, 30, 28, 21, 23, 27, 26)
bin_width <- 3
hist(temperatures, breaks=seq(min(temperatures), max(temperatures) + bin_width, by=bin_width), main="Histogram of Temperatures", xlab="Temperature", col="lightblue")
density_temp <- density(temperatures)
plot(density_temp, main="Density Plot of Temperatures", xlab="Temperature", col="red")
# Run the code to display the plots
# Your code here

Need a hint?

Just run the full code to see both plots in the R plotting window.