# Getting started

Clone your repo `appex05-[github_name]`

to create a new project in RStudio Cloud under the STA 199 class space.

Configure git

```
library(usethis)
use_git_config(user.name="your name", user.email="your email")
```

# Packages and Data

Weâ€™ll make use of the following packages.

```
library(tidyverse)
library(ggpol)
```

# Tasks

## Task 1

Write a function called `center_measures`

that has one argument - `x`

a numeric vector. The function should return the mean and median of `x`

. Below is some sample code.

```
nums <- c(10, 5, -1, 0, 4)
c(mean(nums), median(nums))
```

`#> [1] 3.6 4.0`

```
center_measures <- function() {
}
```

## Task 2

Turn the following code into a function. How many arguments does it need? What is a good name for this function? Assume `x`

will be a nonnegative numeric vector.

`x / sum(x)`

## Task 3

```
congress <- read_csv("http://www2.stat.duke.edu/~sms185/data/politics/congress_long.csv")
congress
```

Write a `for`

loop to compute the number of unique values in each column of tibble `congress`

. Try to stay within the `tidyverse`

syntax as much as possible.

You may find function `length()`

useful. Below are some examples of it in action.

`length(1:10)`

`#> [1] 10`

`length(c("a", "ab", "abc", "abcd"))`

`#> [1] 4`

`length(seq(from = 2, to = 10, by = 2))`

`#> [1] 5`

## Task 4

Function `plot_congress()`

is similar to the function in the slides. I added some annotation so we know the year and legislative branch.

Run the example below to see the change that was made with `annotate()`

.

`plot_congress(year = 2019, leg_branch = "house")`