Hello, and welcome back! In the previous lesson, you learned how to create and inspect data frames in R. Data frames are essential for organizing and analyzing data. Now that you are familiar with the basics, it's time to take the next step — manipulating data frames. This will allow you to modify and manage your data more effectively, enhancing your ability to perform meaningful data analysis.

In this lesson, you'll learn how to:

• Add New Columns: Expand your data frame by adding new columns.
• Remove Columns: Clean up your data by removing unnecessary columns.
• Manipulate Data: Adjust your data to better suit your analysis needs.

Here's a simple example to get you started:

R
Copy
1# Create a data frame
2df <- data.frame(
3  ID = 1:5,
4  Name = c("John", "Jane", "Alex", "Emily", "David"),
5  Age = c(28, 22, 35, 29, 40)
6)
7
8# Add a new column
9df$Salary <- c(50000, 60000, 70000, 80000, 90000)
10
11# Remove a column
12df$Age <- NULL
13
14# Manipulate data
15df$Salary <- df$Salary * 1.10
16
17# Display the manipulated data frame
18print(df)

Note: In many programming languages, NULL is used to represent the absence of a value or an empty object. When you assign NULL to a column of a data frame in R, it removes that column from the data frame. We'll see how this works in the practice!

Being able to manipulate data frames is an essential skill for anyone working with data in R. By mastering these techniques, you can:

• Improve Data Quality: Clean and organize your data for better clarity and accuracy.
• Enhance Analysis: Customize your data frame to fit the specific needs of your analysis.
• Save Time: Quickly adjust your data without having to recreate data frames from scratch.

Manipulating data frames offers you the flexibility to tailor your data exactly how you need it. This will make your subsequent analyses more efficient and insightful.

Are you excited to get hands-on? Let’s move on to the practice section and start manipulating some data frames!