Installing R and (Optionally) RStudio

I will be using R and the sem package for R for the workshop. I assume that attendees will have installed R on their computers, but include these directions to insure that this is the case. If you don't already have a favourite programming editor or interactive development environment (IDE) for R, I recommend that you install RStudio along with R. I will use RStudio for my demonstrations.

R and RStudio are both free, open-source software, available for all commonly used operating systems, including Windows, Mac OS X, and Linux/Unix systems. R and RStudio install in the standard manner on each of these systems. System-specific instructions for installing R are given below. Regardless of your operating system, you should install R before installing RStudio.

Please read and follow these instructions carefully.

Installing R on Windows

Visit the Comprehensive R Archive Network (CRAN) and select a mirror site near you; a list of CRAN mirrors appears at the upper left of the CRAN home page. For example, if you are in Goettingen select the CRAN mirror at GWDG Goettingen. Click on the link Download R for Windows, which appears near the top of the page; then click on install R for the first time, and subsequently on Download R 3.1.0 for Windows (or whatever is the current version of R). Once it is downloaded, double-click on the R installer. You may take all of the defaults, but I suggest that you make the following modifications:

Instead of installing R in the standard location, C:\Program Files\R\R-3.1.0, I suggest that you use C:\R\R-3.1.0. This will allow you to install packages without running R with administrator privileges and will avoid problems that sometimes occur when there are spaces in paths.

In the Startup options screen, select Yes (customized startup). Then (optionally) select the SDI (single-document interface) in preference to the default MDI (multiple-document interface); feel free to make other changes, but you may take all the remaining defaults.

Installing R on Mac OS X

Visit the Comprehensive R Archive Network (CRAN) and select a mirror site near you; a list of CRAN mirrors appears at the upper left of the CRAN home page. For example, if you are in Goettigen select the CRAN mirror at GWDG Goettingen. Click on the link Download R for MacOS X, which appears near the top of the page; then click on R-3.1.0-xxx.pkg (latest version) (or whatever is the current version of R), where xxx is either snowleopard (for OS X version 10.6 or later) or mavericks (for OS X version 10.9) depending upon your version of OS X. Note: Some people have experienced problems with the mavericks build of R for OS X, and so you may prefer to install the snowleopard build even if you are running mavericks. Once it is downloaded, double-click on the R installer. You may take all of the defaults.

Installing R on Linux/Unix Systems

If you have a Linux or Unix system that's not compatible with one of these distributions, you will have to compile R from source code; the procedure for doing so is is described in the R FAQ (frequently asked questions) list.

Installing RStudio

Go to the RStudio home page and click on the Download now button under Powerful IDE for R at the left of the webpage; then click on Download RStudio Desktop. The RStudio website should detect your operating system (Windows, Mac OS X, or Linux); click on the link for the current release of RStudio for your system.

Once it is downloaded, run the RStudio installer and take all of the defaults: In Windows, double-click on the RStudio installer to start the installation; in Mac OS X, double-click on the downloaded RStudio disk-image file, and drag the RStudio icon to the Applications folder.

When you first run RStudio, it should detect your R installation and start the R 3.1.0 console. To configure RStudio to your taste, select Tools > Global Options (Windows) or RStudio > Preferences (Mac OS X) from the RStudio menus. In particular, I suggest that on the General options screen you deselect Restore .RData into workspace at startup, and set Save workspace to .RData on exit to Never. If you encounter difficulties, consult the RStudio troubleshooting guide.

Installing R Packages for the Workshop

Once you have installed R and (optionally) RStudio, you can install theadditional packages required for the workshop by typing the following command at the > command prompt in the R Console (and pressing the Enter or return key):

install.packages("sem")

This will install the sem packages along with its required dependencies. If you wish to install the optional dependencies of the sem package, necessary for some advanced features but not for the workshop, you can instead issue the command:

install.packages("sem", dependencies=TRUE)

You will be prompted to select a CRAN mirror site. Alternatively, you can install the sem package from the RStudio Packages tab.