Exploring world life expectancy

The two data.tables from the previous exercise have been loaded into your workspace:

life_exp: contains the life expectancy of each country in 2010 sourced from the Gapminder foundation
continents: contains a mapping between each country and the continent(s) they are part of built from information provided by Countries-ofthe-World.com.

Your goal this time is to calculate the average life expectancy across countries within each continent.

यह अभ्यास पाठ्यक्रम का हिस्सा है

Joining Data with data.table in R

अभ्यास निर्देश

Inner join life_exp to continents and calculate the mean() (docs) "years" of life expectancy grouped by the "continent" column.

इंटरैक्टिव व्यावहारिक अभ्यास

इस अभ्यास को इस नमूना कोड को पूरा करके आज़माएँ।

# Calculate average life expectancy per continent:
avg_life_expectancy <- continents[life_exp, on = .(country), 
                                  ___][, j = ___, 
                                       by = ___]
avg_life_expectancy

कोड संपादित करें और चलाएँ