 Okay. In this next segment, we're going to introduce you to functions. Functions are where all the magic happens in R, so it's exciting to get here. We're going to start out just as we have in previous sections by creating a new section using our hashtags. I call this section functions and arguments. Don't worry, we'll introduce these terms, explain more we meet by them shortly. You can think of functions as canned scripts. These are lines of code that other people have written and basically stored those in an object. So just as in the previous segment, we created variables stored values. You can do the same thing, storing operations, calculations, that sort of thing. So you can easily use those tools in the context of your exercise. So these have already been stored in either the tidyverse package or the base R set of tools. And I'm just going to go ahead and introduce you to some of the basic ones. The first one we're going to try out is a square root. You type in sqrt followed by parentheses. You can throw a number in here, like 16, run that, and we're going to get the output for. Again, we could store the output of that calculation in a new variable if we wanted to, just by again using the assignment operator here. And as you see, the new variable B is creating our global environment with the value for another really common function that you'll be using is round. That's exactly what you'd expect. It takes the number with multiple decimal places and basically rounds that to the number of places that you indicate. So you can imagine we have high here, rounded to five decimal places. If I run this just for the default, it rounds it up to the nearest whole number of three. Here's something kind of special about these functions that now is a good opportunity to introduce you to, which are arguments. If I wanted to basically customize the output of this function to do something very specific. So instead of rounding the nearest whole number, say round to two decimal places, I can do that using additional arguments. And you separate different arguments within a function using a comma. And you can actually see that as I'm writing this, R is giving me a pop up saying what the arguments that this function takes. So the round function is given here with the number. And then you can give the second argument, which is optional, which is digits equals zero. So if I write here digits equals two and run this, well, now the output, it gives me is going to be 3.14 rounded to do two decimal places. Now you can do the same thing without actually writing digits equals two. Because there are only two arguments being recognized by this function, R just assumes that their second argument is giving the number of digits. As long as your different arguments are in the exact same order as the formula is kind of designed or written, everything runs fine. Where you might run into issues is if you reversed the order. So if instead of having my pie followed by two, I had two by pie. Well, now it's not going to give me the right output. It's going to try basically, in this case, actually it's not even recognizing this as an argument and it's just rounding to the default setting of the nearest whole number. Okay, now on the other hand, if I was to write digits equals two, followed by pie, well, now it understands what I'm trying to do. I've just reversed the order of the arguments. And it's going to give me the expected output pie routed to two significant digits. And likewise, I could do zero significant digits and get back to that default of nearest whole number. So as you can see, there's a lot going on with functions, and it helps sometimes to go to refer to the documentation for these functions to understand both what arguments it takes, what the kind of significance of each of those arguments are. And so the way that you can kind of dig deeper into these functions is using the question mark. If I was to type question mark followed by the function name with or without the parentheses, by the way, then in my bottom right window here in the help tab, the documentation for that round function is going to appear here. And so you'll see here that round is part of the base art package. So it tells you what library or, you know, set of tools that this belongs to. It talks about what it's used for. And also the arguments that it takes and how those arguments should be understood. Okay, it also tell you if some of these arguments are optional, or if there's a default setting, what that default is set to.