dikshashrestha/activity06-pivoting

Activity 6 - Pivot!

It is assumed that you have read Chapters 9 and 10, and 12 from R4DS and completed the Derive Information with dplyr Primer.

In this activity, you will:

• Locate and read data or other files into R using the here::here function.
• Restructure datasets into longer and wider formats using {tidyr}.
• Separate and unite columns into a tidy format.
• Dress up data tables to help with human readability.

☑️ Task 1: The Workflow

Remember that more detailed directions can be found in Task 1 of Activity 4.

Fork this repo and clone it to a new RStudio Project

Planned Pause Point: If you have any questions, contact your instructor or another group.

gather and spread vs pivot_longer and pivot_wider

In the Primer, you learned about the tidyr::gather and tidyr::spread functions. These two functions still exist within the tidyverse; however, they have been superseded and will no longer receive new features. You will often see these “lifecycle” badges on {tidyverse} packages and are meant to provide additional information to users.

Hadley’s introduction to the new pivoting functions can be found at the tidyverse blog.

In the tidyr::gather help documentation (i.e., type ?gather in the Console), we can see how to do similar calls using tidyr::pivot_longer.

df %>% gather("key", "value", x, y, z) is equivalent to df %>% pivot_longer(cols = c(x, y, z), names_to = "key", values_to = "value")

Similarly, in the tidyr::spread help documentation, we can see the similarities to tidyr::pivot_longer.

df %>% spread(key, value) is equivalent to df %>% pivot_wider(names_from = key, values_from = value)

An important thing to recognize between the two pivot_ functions is when we use quotation marks "...".

• For pivot_wider, we are specifying columns that already exist to restructure that information across new columns. Therefore, we do not need to use quotation marks.
• For pivot_longer, we are specifying new columns to restructure the information into. Therefore, we need to use quotation marks.

For this Activity (and in STA 418/518) we will use pivot_longer and pivot_wider.

☑️ Task 2: Complete the RMarkdown File

The activity06-pivoting.Rmd file contains the directions for this activity. For the rest of this class period, you will complete the RMarkdown document with your neighbor(s). Your instructor will be circling and be available to help when needed.

Note that each person is working in their own repo. We are not worrying about collaborating for the time being and instead will be working on being more comfortable with the workflow for working between RStudio and GitHub.

However, do not continue in this README document until you and your neighbor(s) have completed your .Rmd files.

☑️ Task 3: Reflection

Take 5 minutes to draw a concept map that connects what you have learned about pivot_longer and pivot_wider. For example, here is a concept map for dplyr::select:

Next: Activity 7 will focus on combining information from multiple datasets as well and creating maps!