Dependency Management

What is Dependency Management?

Dependency management refers to the practice of defining, managing, and maintaining all the external elements or “dependencies” your project relies on. In the context of programming and data analysis, these dependencies are often software libraries, packages, and specific versions of them.

# A simple code snippet in R might rely on a specific version of a package.
library(ggplot2)
qplot(data = mtcars, x = mpg, y = wt)
Warning: `qplot()` was deprecated in ggplot2 3.4.0.

Why is Dependency Management Important?

  • Reproducibility: Ensuring that your work can be reliably reproduced in the future by yourself, collaborators, or even researchers in a different environment.

  • Stability: As software evolves, new versions might introduce changes that break existing code. By managing dependencies, you can ensure your project remains stable.

  • Collaboration: It allows seamless collaboration, as everyone involved in the project is on the same page regarding which software and versions are used.

Case Study: A Dependency Gone Wrong

Imagine a research project studying the effects of a new drug. The initial analysis, conducted using a specific version of a statistical package, found significant benefits of the drug. The study is published, and the drug is widely adopted.

Two years later, a follow-up study is initiated. However, the original environment and the specific versions of the statistical packages weren’t preserved. The researchers unknowingly use an updated package that introduced a minor change in its algorithm. This time, the results are different, casting doubt on the drug’s efficacy.

This situation not only leads to financial implications but can also impact the reputation of the researchers and trust in scientific studies. Such issues underscore the critical importance of proper dependency management.

Renv: Dependency Management in R

The renv package in R aims to make it easier to manage project dependencies. By isolating the project’s library, you ensure that you’re always working with the correct versions of packages.

# Installing renv
install.packages("renv")

# Initializing renv for a project
renv::init()

# This creates a dedicated library for your project and a renv.lock file that lists all package versions.

Using renv, you can easily share projects with colleagues, confident in the knowledge they’ll be working with the same package versions. If they make changes and add new packages, the renv.lock file can be updated, ensuring everyone remains in sync.

For a more detailed introduction to renv check out this vignette!

Let’s list the dependencies of our project!

  1. In your project, run renv::init(). Take a look at all of the files that it created and try to understand them. Go ahead and push these new files to GitHub!