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Software Package/Environment Management Workshop: R

    • Friday, July 19, 2024

Managing packages and environments in command-line R

In this session, we will begin by using R from the command line. Later, we will cover similar steps using RStudio Server available on Open OnDemand. We will primarily focus on using the renv package for package management, but we will also note alternatives at the end.

Choosing which version of R to use

Multiple R versions are available in the environment module system. Note that modules are named with ‘r’ and the program available after the module is loaded is ‘R’. With each new minor version of R you use, the renv package will need to be installed.

  1. First, use the cluster’s environment module system to find and load the version of R you want to use for your project: module spider r or ml spider r (note the lower-case ‘r’!).
  2. Load the version of R you’d like to use. E.g., module load r/4.3.0 or ml load r/4.3.0.
  3. Run R to open an R session of the version of R you loaded from a module.
  4. Run the R command install.packages('renv') to install renv for this version of R.
  5. Run q() to exit R, and enter n when prompted to save the workspace image.

Creating and managing R environments with the renv package

To use renv for package management, it needs to be associated with an R project. This could be an empty directory if you are just starting a project or it could be one or more R scripts within a directory. Either way, the scope of the renv environment will be dictated by the working directory in which it is initialized. To initialize an renv environment, you use the renv::init() command. For getting started and for this workshop, we recommend passing two arguments when initializing the environment: renv::init(settings = list(use.cache = FALSE, ppm.enabled = FALSE)). These arguments keep package installations within the project directory instead of your home directory and prevent some potentially faulty URL translations from happening when packages are downloaded from repositories.

  1. If you are not already in your workshop directory, change into it by running cd /project/scinet_workshop1/$USER/.
  2. Create and change directory to a project directory: 
     mkdir project1
 cd project1

    Exercise 1: Save the following R code into a file named exercise1.R. (Hint: use nano exercise1.R.) Open an R session and initialize renv for the project. What happens?

     library(magrittr)

 x <- help.search("*", package="base")

 N <- 5
 for(i in c(1:N,N:1)){
     string <- x$matches$Title %>% 
         sample(i) %>%
         cat('\n')
 }

    Exercise 2: What files have been added to the project directory? (Hint: use ls -a to include hidden files).

  3. Run R to open a new R session.
  4. Run the script with source('exercise1.R').

Now we are set up with a project with an renv environment!

Installing and managing R packages in your project library

Next, we will expand our project with additional packages!

  1. You can install packages into your environment as you normally would with install.packages('PACKAGE'), or renv does have an expanded installation function renv::install('PACKAGE') that supports additional remote package sources, e.g., GitHub. If you are interested in learning more about renv::install(), please see the documentation here.
  2. To have renv save the state of the project (i.e., capture all the metadata of the used packages) in the environment configuration file called a ‘lockfile’, run renv::snapshot().

  3. If you want to assess the state of the environment, (i.e., which packages are installed but not used, or which packages are used but not recorded), run renv::status().

    Exercise 3: Save the following R code into a file named exercise3.R. Open an R session. What happens? Modify the environment to be consistent and to make the program run. What does the updated program do?

     library(magrittr)
 library(cli)

 x <- help.search("*", package="base")

 N <- 7
 for(i in c(1:N,N:1)){
     string <- x$matches$Title %>% 
         sample(i) %>%
         col_magenta() %>%
         cat('\n')
 }

Reproduce renv projects

In order to make environments and package management truly useful, we need a mechanism to easily reproduce environments. With the renv project files we looked at before, you can have renv reproduce the same environment in a new project directory.

  1. The renv directories and files that should remain with the project are the renv.lock file, the renv/activate.R and renv/settings.json files, and the .Rprofile file. With these files, the project environment can be easily recreated, therefore helping to ensure that your code and analyses are fully reproducible.

  2. If you are using git for version control for the project, renv adds the renv files that do not need to be tracked (i.e., the packages themselves) to the .gitignore file for you.

    Exercise 4: Create a new project directory in your workshop directory (i.e., at the same level as project1 and not within it). Copy over all of project1’s files except renv/library and renv/staging (the package files) into the new project. From the new project directory, run R. What happens?

Managing packages and environments in RStudio Server

The approach of using renv in RStudio is very similar to using renv with command-line R. For completeness, we will create another environment in RStudio Server.

Choosing which version of R to use

Multiple R versions are available when requesting RStudio Server sessions on Open OnDemand. From the Open OnDemand page, select “Interactive Apps” > “RStudio Server”. You will be taken to a page with multiple input fields to configure your RStudio Server session and one of those is “R Version”.

  1. For the following exercise, select the following inputs:
    • Account: scinet_workshop1
    • Queue: short——–Max Time: 2-00:00:00
    • QOS: 400thread
    • R Version: 4.3.2-EL9
    • Number of hours: 1
    • Number of cores: 2
    • Memory required: 8G
    • Optional Slurm Arguments: --reservation=scinet_workshop1
  2. When you are in RStudio Server, install renv.

Creating and managing R environments with the renv package

Since renv is project specific, you need to change the working directory to the project directory in which you would like to use renv. Once in the project directory, you can run renv::init(settings = list(use.cache = FALSE, ppm.enabled = FALSE)) to start managing the project environment with renv.

In RStudio Server, there are also additional graphical features in the interface when renv is active. E.g., note that there is an “renv” button at the top of the “Packages” pane. If you click on it, there is a dropdown menu that includes shortcuts to the renv::snapshot() and renv::restore() functions.

  1. Create a new project directory.
  2. Initialize renv for the new project with renv::init(settings = list(use.cache = FALSE, ppm.enabled = FALSE)).
  3. Add at least one script to the project and install the packages it uses with either install.packages('PACKAGE') or renv::install('PACKAGE').

  4. Take a snapshot of the environment with renv::snapshot() to update the lockfile.

    Exercise 5: Use the renv::install() function to download the development version of the ‘nsyllable’ package on GitHub at ‘quanteda/nsyllable’. Save the script below as an R script in your project directory. What does the program do? Use the “renv” button in the “Packages” pane to make sure this project’s lockfile captures the new package. Open the renv.lock file to see the entry for the new package.

     library(magrittr)
 library(nsyllable)

 x <- help.search("*", package="base")
 x$matches["nsyl"] <- nsyllable(x$matches$Title)

 for(i in c(5,7,5)){

 correct_length <- x$matches$nsyl == i 

 string <- x$matches$Title[correct_length] %>%
         sample(1) %>%
         cat('\n')
 }

If you don’t want to use renv

renv is the main solution if you want a handful of commands to manage a project’s packages with a project-specific library and also document that process to increase reproducibility. If, for any reason, you are not a fan of renv, there are some commands and R-related files that can help you at least manage the locations of package installations.

R commands:

  • .libPaths(): This function returns the path(s) of available libraries from which packages may be loaded. If there are multiple libraries available (i.e., if .libPaths() returns multiple paths), R will search for packages across libraries in the order in which .libPaths() lists the library paths. The function can also be used to add additional available libraries: e.g., .libPaths('/path/to/new/library') will prepend “/path/to/new/library” to the list of available libraries, making it the first library searched in when loading packages. It is thus very handy to call .libPaths('/path/to/project/library') to make your project-specific library the first place in which packages are searched for loading. However, changes to .libPaths() only persist during the R session in which it was run.
  • install.packages(): When you install R packages with install.packages(), the default location for installing those packages is in the first library path returned by .libPaths(). If you want a package installed somewhere else besides that first library path, you can specify the desired path with the lib parameter in install.packages(): e.g., install.packages('PACKAGE', lib=‘path/to/the/project/library’).
  • library(): When loading a package with library(), R will search for packages across libraries in the order in which .libPaths() lists the library paths. If you instead want to specify the library path from which a package should be loaded, you can use the lib.loc parameter in library(): e.g., library(PACKAGE, lib.loc='path/to/the/project/library').

R-related file:

  • .Renviron: You can specify R environment variables in this file, including R_LIBS_USER which is a path that will be prepended to the library paths maintained by .libPaths(). For example, if you have R_LIBS_USER=path/to/the/project/library/%v in your .Renviron file in a directory, any R session started from that directory will first look in R_LIBS_USER=path/to/the/project/library/%v, where %v is the version of R being used, for packages to load.