R self-assessment test and further pointers.
This is a short self-assessment test* for participants who are unsure if they have enough experience with R. If you are able to solve the exercises below (also with the help of Google and Stackoverflow), you have enough experience with R for the course. If not, below the exercises you will find links to some R crash courses that you have to go through on your own (you don’t have to go through all of them, choose the one(s) you like the best) before you take our course.
Using function rep() create a numerical vector with 24 elements that repeats the following sequence 4 times c(1, 2, 3, 4, 5, 6)
.
Create a dataframe named df_cake
with twenty rows and four columns: Person, Age, Cake, Coffee
. Populate column Person
with twenty names of your choice. Populate column Age
with ten random numbers between 18 and 80. Column Cake
should be populated with cake names from the following vector in random order c("Tiramisu", "Lemon Tart", "Brownie", "Cheesecake", "Carrot Cake")
. Column Coffee
should be randomly populated with 0 and 1, where 0 means that the person did not have coffee with their cake, and 1 that they had coffee with their cake.
Now answer the following questions about the resulting dataframe:
Write a function called blueberry
that would replace all the values equal to Carrot Cake
in a dataframe with Blueberry Cake
. Now apply this function to your df_cake
dataframe.
Add a column Age Group
to your df_cake
dataframe. Assign value Youth
to Age Group
for people whose Age is between 18 and 25. If a person’s Age is between 25 and 65, set their Age Group
to Adult
. If their Age is over 65, set their Age Group
to Senior
.
Links to R crash courses:
*This test is adapted from a test developed by Ueli Reber, Thomas Hauessler and Aleksandra Urman for students of the University of Bern in Fall 2020.