Code Functions and Arguments

Question 1

At the start of an R script, we would like to install and load the package called {janitor}. What code chunk is recommended to have in your script?

Answer 1

if(!require(pacman)) install.packages(“pacman”)

pacman:p_load(janitor)

Question 2

The function [BLANK] will give you the number of rows and columns in a dataset (e.g., for “ebola_sierra_leone” dataset).

Answer 2

dim(ebola_sierra_leone)

Question 3

Using the [BLANK] function gives you a tabular summary of the common values for a categorical variable.

Answer 3

inspect_cat

Question 4

To extract a single variable/column from a dataset (e.g., “ebola_sierra_leone”), use the [BLANK] operator.

Answer 4

$ (e.g. ebola_sierra_leone$age)

Question 5

To create a frequency table on the ebola_sierra_leone dataset for the district and age variables, a useful function to use is:

Answer 5

tabyl(ebola_sierrra_leone, district, age)

Question 6

Which function can you use to save plots to images with a specific file name? Use an example.

Answer 6

ggsave()

Ex: ggsave (filename = “output/categorical?plot.png”, plot = categ_vars_plot)

Question 7

[BLANK] is good for showing very large tables in HTML by giving your audience the option to scroll through the tables.

Answer 7

reactable

Question 8

To check the class of the age vector, you would type:

Answer 8

class(age)

Question 9

Create an improved version of a data frame called data_epi (hint: tidyverse package).

Answer 9

tibble_epi <- as_tibble(data_epi)

Question 10

This function can be used to import data and will automatically give you a tibble.

Answer 10

read_csv