Introduction to data frames
Data frame structure
Accessing columns in a data frame
Accessing rows of a data frame
Accessing rows and columns combined in a data frame
Data frame analysis
28. Analyzing filtered data frames
Summary

Instruction

Great! Of course, you can apply all data frame analysis functions to filtered data frames. Let's try this in an exercise.

Exercise

How many countries have more than 50 million people? Use the countries data frame to extract the rows that match this condition, and use them in your analysis.

Stuck? Here's a hint!

Use nrow(), and pass in a data frame that is a subset of the original table. You can do so with the following code:

countries$population > 50000000