Finding missing observations
You're an inspector at a nuclear plant and have to validate whether every reactor has received its daily safety check over the course of a full year. The safety check logs are in reactor_df
, a data frame with columns date
, reactor
, and check
.
Two vectors, dates
and reactors
, with all dates of the year and reactors at the plant respectively have been created for you.
You'll use the combination of the expand_grid()
and anti_join()
functions to find dates where particular reactors were not checked.
The dplyr
package has been pre-loaded for you.
This exercise is part of the course
Reshaping Data with tidyr
Exercise instructions
- Use the
expand_grid()
function to create a tibble holding all combinations of the variablesdate
andreactor
. Use thedates
andreactors
vectors created for you. - Perform an anti-join between
full_df
andreactor_df
on thedate
andreactor
columns.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Create a tibble with all combinations of dates and reactors
full_df <- ___
# Find the reactor - date combinations not present in reactor_df
full_df %>%
___