This lecture is on installing Rtools. This lecture is primarily useful for people using Windows computers. People that are using Mac or Linux don't necessarily need this lecture. So Rtools is a collection of tools that are necessary for building R packages in Windows. We won't be doing that right away, but later in developing data trials you will be doing that, so you need to be able to install Rtools if you're going to complete that class. And so, Rtools is available for, download at this website up here, as I've listed it. And so, what you can do is you can find a version of Rtools that is available that is the latest version, and so you want to select the .exe download link, and it corresponds to your version of R, so you need to figure out what version of R you have. And then, download that version, if you are not sure what version of R you have, open and restart R and you will see in the very beginning there will be some text listed out and one of the things they list out in that text is the version of R. If you, have the most recent version of R, you should select the most recent Rtools download, it's at the top of the chart. And so, if you just installed R for this course, then you will also need the latest version of Rtools. Once the download completes, you'll just open the executable file to begin the installation. So basically unless you know what you're doing, you should just go with the default selection at each steps of the installation. There only two steps worth noting, so if you already have Cygwin installed on your machine, you should just follow the instructions given during installation, and those instructions are also at this URL. And you should make sure that box is checked to have the installer edit your path. And so you can see it very, very, if you're very eagle eyed, in this below. But basically make you sure check the box to allow the installer to edit your path. Once the Rtools installation completes, you can open our studio, and you install the dev tools package if you don't already have it. So, if you type find.packages("devtools") in the console, you'll figure out whether you have it or not. And then to install it, you can just, as in previous lectures, just use install.packages("devtools") like that, and you'll have the devtools package. After devtools is done installing you can load it using library(devtools) and then type find_rtools(), like this as shown below, and this should return a TRUE. So you should see TRUE printed out on the screen if Rtools installation has worked properly and you'll be ready to go.
