Mastering simple joins
Three new data.tables
have been loaded into your R session containing information about the geography and population of Australia: area
, capitals
, and population
. Your goal is to perform a sequence of joins to build a single data.table
containing information about the geographical area of each Australian state and the population of its capital city, storing the final result in a new variable: australia_stats
. There are three data.tables
so you will need to perform two joins. First, you will join capitals
and population
, and then you will join the resulting data.table
to the area
.
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.
# Identify the key for joining capitals and population
capitals_population_key <- ___
# Left join population to capitals
capital_pop <- ___
capital_pop