col_types with collectors

Another way of setting the types of the imported columns is using collectors. Collector functions can be passed in a list() to the col_types argument of read_ functions to tell them how to interpret values in a column.

For a complete list of collector functions, you can take a look at the collector documentation. For this exercise you will need two collector functions:

col_integer(): the column should be interpreted as an integer.
col_factor(levels, ordered = FALSE): the column should be interpreted as a factor with levels.

In this exercise, you will work with hotdogs.txt, which is a tab-delimited file without column names in the first row.

hotdogs is created for you without setting the column types. Inspect its summary using the summary() function.
Two collector functions are defined for you: fac and int. Have a look at them, do you understand what they're collecting?
In the second read_tsv() call, edit the col_types argument: Pass a list() with the elements fac, int and int, so the first column is imported as a factor, and the second and third column as integers.
Create a summary() of hotdogs_factor. Compare this to the summary of hotdogs.

Exercise

col_types with collectors

Instructions