Casting a long table
gdp_oceania contains the population and GDP for every country in Oceania for every five years from 1990 to 2010 and is available in your workspace. Your goal is to create wide format data.tables containing the population and total GDP for each country with each year having its own column.
This exercise is part of the course
Joining Data with data.table in R
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Split the population column by year
___(gdp_oceania, formula = ___ ~ ___, value.var = "population")