Tables in R - Data frames and tibbles

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1 Task

Note

Find the solution here.

1.1 Get started with tibbles

Before you start the task:

• Install the tibble package by calling install.packages("tibble") in the console.
  • You don’t need to put this command in your script as you only need to call it once to install the package
• Open your script for the task and put library(tibble) on top
• Execute this line and the tibble package is loaded into your R session

1.2 Create a tibble

Use the vectors species, brainwt_kg, bodywt_kg from before and combine them in a tibble.

1.3 Explore the tibble

Explore the tibble you created with the different functions that you learned in the presentation. You can for example try

• view() and explore what you can do in the view window that opens: searching, filtering, sorting columns
• summary()
• …

1.4 Index, filter and select

Now let’s try some indexing on the data.

• Rows 1, 5, and 7 and the columns species and bodywt_kg
• Filter rows 1 to 10, all columns
• Select the column bodywt_kg as a vector

1.5 Extra

• Select the last column of the last row without using the row and column index (so don’t use any numbers in this command)
• Calculate the mean of the bodywt_kg column and save it in a variable
• Add a new column to the data called ratio_body_brain with the ratio of the columns bodywt_kg and brainwt_kg