When it comes to reshaping data in R, there are often multiple ways to achieve the same result. One common task in data manipulation is converting wide data into long data, and two popular functions for this purpose are pivot_longer and gather. Both functions serve the same fundamental purpose, but they belong to different versions of the tidyr package in R. In this article, we’ll explore these two functions and discuss reasons for choosing one over the other.

Understanding the Basics

Before delving into the reasons for choosing one function over the other, let’s clarify what these functions do:

– pivot_longer: This function is part of the newer tidyr package in R. It is used to transform wide data into long data. The primary idea is to specify the columns you want to pivot into a longer format and create two new columns: one for variable names and another for their corresponding values.

– gather: The gather function is part of the older version of the tidyr package in R. It serves the same purpose as pivot_longer but uses different syntax. It pivots selected columns into a longer format, specifying the key column for variable names and the value column for variable values.

Why Choose pivot_longer?

 1. Modern Syntax: If you are using a more recent version of the tidyr package or prefer a more modern syntax, pivot_longer might be your preferred choice. It aligns with the latest best practices in data manipulation.

 2. Readability: pivot_longer has a more explicit syntax with clear argument names like cols, names_to, and values_to. This can enhance code readability, making it easier to understand at a glance.

 3. Consistency: If you’re already using other functions from the newer tidyr package, such as pivot_wider, using pivot_longer keeps your code consistent and minimizes the need to switch between different syntax styles.

Why Choose gather?

 1. Legacy Code: If you have existing code or scripts that use the older version of tidyr, switching to gather might be more convenient and maintainable to ensure compatibility.

 2. Familiarity: Some R users may be more accustomed to the gather function, especially if they have been using R for a longer time. Choosing gather can be a matter of personal preference and familiarity.

 3. Documentation and Resources: Since gather has been around for a longer time, you might find more documentation and online resources related to its usage. This can be beneficial for troubleshooting and learning.

Conclusion

In the end, whether you choose pivot_longer or gather depends on your specific needs, coding style, and the version of the tidyr package you are using. Both functions are powerful tools for reshaping data, and the choice between them should be based on factors like readability, compatibility, and personal familiarity.

If you’re starting fresh or have the flexibility to choose, pivot_longer offers a more modern and explicit syntax. However, if you have legacy code or prefer the older syntax, gather is a perfectly valid choice. Ultimately, the goal is to transform your data efficiently and effectively, and either function can help you achieve that goal.