Completing the Solar System
You have been given a data frame (planet_df) from the devstronomy project with the number of moons per planet in our Solar System. However, Mercury and Venus, the two moonless planets, are absent. You want to expand this dataset using the complete() function and a vector planets that contains all eight planet's names.
This exercise is part of the course
Reshaping Data with tidyr
Exercise instructions
- Complete the
planetvariable using theplanetsvector. - Replace
NAvalues in then_moonsvariable with0Lvalues.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
planets = c("Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune")
planet_df %>%
complete(
# Complete the planet variable
___,
# Overwrite NA values for n_moons with 0L
___
)