Expecting mapped output
When you know that the output of your mapped function is an expected type (here it is a numeric vector) you can leverage the map_*() family of functions to explicitly try to return that object type instead of a list.
Here you will again calculate the mean population of each country, but instead, you will use map_dbl() to explicitly append the numeric vector returned by mean() to your data frame.
Cet exercice fait partie du cours
<cours>Machine Learning in the Tidyverse</cours>Instructions de l’exercice
- Generate the
pop_meandata frame using themap_dbl()function to calculate the population mean for each nested data frame. - Explore the
pop_meandata frame usinghead().
Exercice interactif pratique
Essayez cet exercice en complétant ce code d’exemple.
# Calculate mean population and store result as a double
pop_mean <- gap_nested %>%
mutate(mean_pop = map_dbl(___, ~mean(.x$___)))
# Take a look at pop_mean
head(___)