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.
แบบฝึกหัดนี้เป็นส่วนหนึ่งของหลักสูตร
Reshaping Data with tidyr
คำแนะนำการฝึกหัด
- Complete the
planetvariable using theplanetsvector. - Replace
NAvalues in then_moonsvariable with0Lvalues.
แบบฝึกหัดเชิงโต้ตอบแบบลงมือทำ
ลองทำแบบฝึกหัดนี้โดยเติมโค้ดตัวอย่างนี้ให้สมบูรณ์
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
___
)