Hi and welcome to the lecture on Shiny. My name is Brian Caffo. Shiny is really the cornerstone of this class because it's the tool that we're going to use to develop data products. So Shiny is, let me advance the slide here. Shiny is a web development framework in R. And the nice thing is you only really need to know R. You can use R in the back end, use R to actually write the user interface. And you don't need to know the standard tools like JavaScript, HTML, and so on. But I'll talk a little bit more about that. Let me just talk about Shiny more broadly first and then we'll get more into the details. So broadly, Shiny has been more of a revolution among those data scientists that really specialize in R and focus on developing algorithms, and analysis, and that component. Of course, if you work in web development proper and that's the direction you're coming to data science from, then you probably have a different tool set. You probably wouldn't elect to use Shiny because you already have so many tools already at your disposal. But if you come from this other end, then Shiny is a great way to prototype potential data products. It's a great way to create small data products that you would deploy if you're a smaller organization. Or if you're a big organization, you might create something as a prototype, and then send it off to people with these other skills that would maybe convert the R code to some compiled language, write a super nice JavaScript front-end, and have a bunch of fancy HTML. But the nice part about Shiny is we do everything in R. We create the GUI in R, the algorithms and everything else that are powering it in terms of the data science part is all written in R and so on. And your time to create a data product is completely minimized. So Shiny is made by R Studio, it's free, it's just an R package. What might cost you is you have to host Shiny on a server, right? So, it's a web development framework. You need to actually have a web server that is not only going to serve up the web pages but is also going to call R in the back end to call your algorithms, or your models, or whatever. So Shiny itself is free and open-source, I think it's open-source. But the hosting might cost you, so RStudio has this free hosting service, and that's what we're going to use for the class. And you can run your smaller applications through RStudio's free hosting service. The other two options you have at your disposal would be to create your own server, which you could run off of AWS or something like that, Amazon AWS. Or you could do something like Shiny's paid service. The other thing you can do is you create Shiny apps locally, and you test and debug them locally. You can give a Shiny app to another person who uses RStudio, and they can use it in the web browser just like, I'm sorry, in RStudio just like you do. And so, if portability at that level is what you need, then you don't actually need the web server part. But really, the interesting component about this is making a web server that anyone can use that displays your data analysis, or your prediction algorithm, or what have you. And Shiny gives you a pretty easy way to do that. So we'll talk later on more about the server and how to use shinyapps.io, which is going to be the free server we use in this class. And so, today we're just going to get you started. We're going to go from zero up to having a running little web server with running R as the back end. Okay, so some mild prerequisites. Like I said, you do everything in R, but I think it would be kind of hard to do this without knowledge of a little bit of HTML. CSS and JavaScript I actually think you don't need to know any of to do Shiny. But a little bit of HTML just to give you some of the basics of what the commands in R are actually doing, that would be super useful. And we're not going to teach that here. There's a million HTML tutorials on the Internet. Just find any, create a basic web page, learn what some of the basic commands are and the format of them, and that's all you need. Shiny uses this Bootstrap package, which has no relations to the statistics bootstrap, which looks nice and I think it renders well. It's the folks at Twitter came up with it. So it creates, it has a nice set of buttons and things like that that I think resize correctly hen you have your page rendered on a small device like a phone or on a big screen as well. So they've thought through that. I think Bootstrap, if you don't know a lot about that kind of web development, then just stick with the Bootstrap themes. And so again, I just give you some more tutorials if you want to learn about the three core components of at least the front end of the kind of applications we're going to be developing. HTML, CSS will give you the style, and JavaScript is what gives you all the interactivity. I'm giving you some tutorials there. Most importantly, do some of the HTML one. Okay, so getting started, you got to install Shiny, install.packages("shiny"). And then whenever you get it working with Shiny, you gotta make sure it's loaded up, so library(shiny). And then there's a, before you even start this, you might even consider the official Shiny tutorial at RStudio. And mostly this lecture is walking through that tutorial. Okay, so I'm going to start going through some code demonstrations here in a minute, but let me just go through the basics really quick. What you need for a Shiny project is you need ui.R, a file called ui.R, and a file called server.R. So ui gives you the user interface, and it'll determine how your app looks and server.R will control what your app does. Okay? Now I'm going to switch over and start doing some code demonstrations and so stay tuned
