How to Stack Two Columns into One in R using data.table

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When working with data in R, it is common to manipulate data frames for various analytical purposes. One such operation is stacking two columns into one. This can be particularly helpful if you want to condense your data for easier visualization or analysis. In this guide, we'll explore how to transform a simple data table by merging two columns into a single column.

Understanding the Problem

Let’s say we have a data table with the following structure:

IDAB142253Our goal is to rearrange this data so that the columns A and B are stacked into one new column, which we'll call C, while retaining the ID column. The expected output would be:

IDC14122523The Solution

Steps to Stack Columns

Load the Necessary Libraries
Ensure you have the required packages installed and loaded in R. You can do this by running the following commands:

[[See Video to Reveal this Text or Code Snippet]]

Create Your Initial Data Frame
We start by creating the original data frame in R:

[[See Video to Reveal this Text or Code Snippet]]

Transform the Data Frame
Next, we will stack columns A and B into a single column C using the pivot_longer() function. The code for this operation is as follows:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Code

pivot_longer(cols = c(A, B), values_to = "C"): This line selects the columns A and B to stack into one new column C.

select(-name): After pivoting, a new column 'name' is created which indicates the original column names. We can remove this to get our desired output.

Final Output

If you print df1_long, you will see:

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This will yield:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Feel free to experiment with your own data frames using this method, and don’t hesitate to reach out in the comments if you have any questions or need further assistance!