4 Individual package information

Clicking on a package in search results or in a universe overview will take you to the homepage for that package. You can also link to this page directly using the url https://{owner}.r-universe.dev/{package}.

4.1 Package Homepage

Landing page for the sf package, displaying much information including installation instructions. — Landing page for the sf package

Citation for the sf package. — Citation for the sf package

Each package page is automatically generated and provides:
- Detailed information about the project,
- Installation instructions for quick setup in R,
- Other relevant resources.

4.2 Website tour

To explore the information provided on the R-universe page for each package, you can:
- Read this documentation chapter, or
- Click the “Website Tour” button in the navbar for an interactive guide.

4.3 Package information

The initial section of the homepage shows descriptive data and links to resources from this package, such as source/binary files, the package manual and NEWS file. Further down we show installation instructions to install the package in R. Installation is quick and easy because we provide pre-compiled binaries for Windows and MacOS, so no special tools or setup is required on the user machine.

Here you can also find more information derived by the build system, such as which system libraries the package builds on, topics, and if the package is on CRAN. The badges underneath show statistics about the package, such as dependencies, reverse dependencies, and GitHub stars. Clicking on the ’exports’ badge will show all functions and datasets exported by the package, which link to the respective sections in the manual page. If specified, we also show how the package should be cited in papers.

4.3.1 How are the dependencies / dependents calculated?

Dependencies and dependents are derived using transitive (recursive) strong dependencies. Hence this includes both direct and indirect dependencies.

Dependencies: Other packages required to use the target package.
Dependents: Packages listing the target package as a dependency.

At package build time, we use tools::package_dependencies(pkg, recursive = TRUE) to compute the list of hard dependencies, excluding R-base packages. The size of this list determines the dependencies value, while the dependents value reflects the number of packages in R-universe depending on the target package.

4.3.2 How does R-universe analyze system dependencies (C/C++)

After the package has been installed, we use maketools to show external libraries that the package links to:

maketools::package_sysdeps("sf")
##                 shlib      package     headers source              version
## 1   libproj.so.15.3.1    libproj15 libproj-dev   proj              6.3.1-1
## 2   libgdal.so.26.0.4    libgdal26 libgdal-dev   gdal   3.0.4+dfsg-1build3
## 3 libgeos_c.so.1.13.1 libgeos-c1v5 libgeos-dev   geos        3.8.0-1build1
## 4 libstdc++.so.6.0.28   libstdc++6        <NA>    gcc 10-20200411-0ubuntu1

In a nutshell, maketools calls ldd on the installed R package to see which .so files are linked (the 1st column above). Then it uses the distro package manager (for instance dpkg) to query the runtime package deb that provides this file (the second column), and the corresponding headers and source packages. So to emphasize, this does not use heuristics / guessing based on the package description.

The maketools vignette explains this in more detail: Automatically determine run-time dependencies for R packages on Linux.

See also how to request a third-party system that your package needs.

4.4 All the documentation

R-universe renders and presents all available documentation to help you start using packages quickly.

README of the sf package. — README of the sf package

Manual of the sf package, displaying a list of all functions in the package, hyperlinked. Documentation of one function of the sf package.

Most R packages have 3 forms of documentation: a README file, a reference manual (help pages), and a number of articles (including vignettes). These articles are often a good place to get started, and are listed on the package homepage right under the descriptives. From here you can view both the rendered html/pdf document, as well as the rmarkdown source file used to (re)produce the article.

Further down the page you can see the content from the package README. Most packages these days include a README.md file which can nicely be rendered into HTML.

After the README follows a section named “reference manual” containing a table with all the help pages. These link to the respective chapters in the html reference manual, which provide the most extensive documentation for each function in the package, including descriptions, parameters, examples, etc.

4.4.1 cran.dev shortlinks

On R-universe you can find package repositories from many different organizations and maintainers. But sometimes you just want to lookup a particular CRAN package, without knowing the developer. The cran.dev shortlink service lets you navigate or link directly to the R-universe homepage and docs of any established CRAN package.

The root domain https://cran.dev/{package} redirects to the primary homepage for a package:

The subdomain https://docs.cran.dev/{package} redirects to package manual page:

Finally the subdomain https://api.cran.dev/{package} does not redirect, but returns a JSON blob with links to the package versions and resources. For example:

https://api.cran.dev/gert

This shows the package page and maintainer for the gert package, and information on both the current CRAN release and development versions. Right now it returns:

{
  "package": "gert",
  "maintainer": "Jeroen Ooms <[email protected]>",
  "home": "https://ropensci.r-universe.dev/gert",
  "release": {
    "version": "1.9.2",
    "date": "2023-06-30T08:43:26.000Z",
    "source": "https://github.com/cran/gert",
    "repository": "https://cloud.r-project.org",
    "docs": "https://cran.r-universe.dev/gert/doc/manual.html",
    "api": "https://cran.r-universe.dev/api/packages/gert"
  },
  "devel": {
    "version": "1.9000",
    "date": "2023-07-20T11:08:09.000Z",
    "source": "https://github.com/r-lib/gert",
    "repository": "https://ropensci.r-universe.dev",
    "docs": "https://ropensci.r-universe.dev/gert/doc/manual.html",
    "api": "https://ropensci.r-universe.dev/api/packages/gert"
  }
}

We can see the release and devel version of this package, with links to the respective sources, cranlike repository, manual, and package metadata.

From the above it can be seen that the gert R-universe page is https://ropensci.r-universe.dev/gert and the R-universe "repository" from where to install the devel version of gert:

# install 'devel' gert
install.packages("gert", repos = "https://ropensci.r-universe.dev")

The "api" field shows the JSON url with all the information and metadata about this package:

# Everything there is to know about devel gert
gert <- jsonlite::fromJSON('https://ropensci.r-universe.dev/api/packages/gert')

Note that not all packages have a devel version available. CRAN packages that are not found on GitHub or GitLab or R-forge only have a release version, for example: https://api.cran.dev/MASS

4.5 Usage and development activity

Warning

The information on development is only accurate if the developers push to the tracked Git repository. If for instance a maintainer updates a package on Bioconductor or CRAN without updating the Git repository, the information on R-universe will be stale.

Besides familiarizing yourself with what the package does, you may be interested in who is working on it, who else is using it, and if it is still actively developed.

The “development and contributors” section shows a bar chart with the number of commits per week for the last year, and who the main contributors are. Finally the section “usage by other packages” shows other packages on R-universe depending on this package, grouped by owner. This gives you some indication on how active the project is, and who are involved.