How to Change the Installation Location of R Packages

When working with R, you might find a situation where you need to change the default installation location of R packages. Whether you want to save space, organize your packages, or just prefer a specific path, this guide will show you how to do it effectively.

Understand the Default R Package Library Path

R uses a single package library for each installed version of R on your machine. This default location is typically something like C:/Users/Username/Documents/R/win-library/3.6 for Windows or /home/Username/R/x86_64-pc-linux-gnu-library/3.6 for Linux, where 3.6 is the current R version. However, this path can be changed to suit your needs.

Change the R Package Library Path

To change where R installs your packages, you have to call the function .libPaths() and specify the new library location. This function returns the current library search path, which is a list of directory names where R looks for packages. By modifying this list, you can add or remove library paths as per your requirements.

Adding a New Library Path

Adding a new library path is straightforward. Simply call .libPaths() with the new path as an argument. Here's an example in R:

.libPaths( c( .libPaths(), 'D:/MyCustomLibrary' ) )

In this example, 'D:/MyCustomLibrary' is the new location you want to add. This command will add this new path to the existing list of paths R uses to search for packages.

Modifying the Current Library Path

If you want to modify the current library path, you can do so in a similar way. For instance, if you want to remove the default library path and set a custom one, you can do the following:

.libPaths( 'D:/MyCustomLibrary' )

This will set the new path as the sole location R will check for packages. Remember to remove any other paths that might not be necessary to avoid conflicts.

Best Practices for Managing R Package Libraries

Managing package libraries effectively can greatly enhance your workflow. Here are some best practices:

Keep your package libraries organized by version of R. This helps in easily updating and maintaining your packages across different R versions. Consider using symbolic links (symlinks) on Unix-based systems to point to the same library directory from multiple R versions. This can be particularly useful if you have multiple versions of R installed. Install development libraries in a separate directory to keep them separate from your main R packages. This prevents accidental overriding of important files.

Conclusion

Changing the default R package library path is a simple yet powerful feature that can greatly enhance your R programming experience. Whether you're working on a project with strict file storage requirements or just prefer a more organized workspace, customizing your package library path can make a significant difference.

Frequently Asked Questions (FAQs)

Q: How do I find the current R package library path?

A: You can find the current R package library path by calling the function .libPaths(). This will return a list of directories R searches for packages.

Q: What happens if I remove the default library path?

A: Removing the default library path will cause R to search only for packages in the directories specified in the .libPaths() function. You can specify a single custom path to use as the only location for package installation.

Q: Can I use different library paths for different R versions?

A: Yes, you can use a different library path for each R version. Simply call .libPaths() with the appropriate path before starting R, or modify the lib.loc argument in the () function.