paste(nrow(available.packages()),
"packages on CRAN on",
Sys.Date())[1] "21695 packages on CRAN on 2024-11-25"R for modellers - Vignette 03
Installing and loading packages
Julien Arino
Department of Mathematics
University of Manitoba*
* The University of Manitoba campuses are located on original lands of Anishinaabeg, Cree, Oji-Cree, Dakota and Dene peoples, and on the homeland of the Métis Nation.
Required for MATH 2740 students!
- If you are a student in the University of Manitoba’s Mathematics of Data Science (MATH 2740) course, you must read the “friendly” method
- In particular, failure to use this method may result in loss of marks in your
Rassignments!
Packages (a.k.a. libraries)
Why use packages?
- Packages (or libraries) extend
Rby providing functions or data that are useful in particular contexts
- Packages allow to avoid “bloating”, since the
Rcore remains relatively light and you only install the additional content you need
CRAN is the main source for packages
There are also packages not on CRAN
- For instance, packages on GitHub
- Sometimes packages get removed from CRAN, although the latest versions are typically still available
- Installation is a little different (detailed later)
Installing a package
From CRAN
- Use the command
install.packages()
- However, do read the section on the “friendly” method
- You can also use RStudio
From GitHub
- Some packages are only on GitHub; others have their latest (testing) version on GitHub and a stable version on CRAN
- Need to use the
devtoolsorremotespackages (maybe preferdevtools)
- You can also use the package githubinstall
Example: xkcd style graphs
Installing a removed package
- Example: htmltab
- Grab the newest archived version from CRAN
or we can point directly to the link
Loading a package
Loading a package
- Once a package is installed, you load it with the command
library()
- No need to use quotation marks:
library(ggplot2)
- You can also use RStudio
Loading several packages
To load several packages with a single command, you need to use a loop and the option character.only = TRUE
Be friendly to others
When distributing your code, think of those using it
If you use a slightly unusual library, it is possible that a person you share your code with does not have that library installed
- It is nice to them if you spare them having to do the work to install the library
But it is also possible that they already have the library
- It will be annoying to them if you trigger an installation of the library (especially under linux where libraries are compiled for installation)
So test whether the library is installed
- If it is, load it
- If it is not, install it then load it
requireis designed for use inside other functions; it returnsFALSEand gives a warning (rather than an error aslibrary()does by default) if the package does not exist.
Example using several libraries
Updating packages
Using RStudio
- RStudio has a menu to check if updates are available to libraries and update them if that is the case
From the R command line
ask = FALSE: do not ask for confirmationcheckBuilt = TRUE: check with which version ofRthe package was built and call package old if this is a earlier major version (e.g., built with 4.2 when the current is 4.3)Ncpus = 6: run compilations (if needed) using that many threads
Packages and R major versions
- Packages are stored by default in your home folder under the current major version of
R(currently 4.3)
When the major version changes, you therefore need to do something with all your current packages..
There is no planned mechanisms for doing this!
Easiest: export list of libraries in the previous version, then install all of them
Set lib to be previous R version (the one prior to the update), say, 4.2:
then get list of packages
then use the method described earlier to install all these packages
R for modellers - Vignette 03 Installing and loading packages Julien Arino Department of Mathematics University of Manitoba* * The University of Manitoba campuses are located on original lands of Anishinaabeg, Cree, Oji-Cree, Dakota and Dene peoples, and on the homeland of the Métis Nation.