---
title: "NYC flights data wrangling example"
author: "Nicholas Horton (nhorton@amherst.edu)"
date: "June 14, 2021"
output: 
  pdf_document:
    fig_height: 7
    fig_width: 8
  html_document:
    fig_height: 3
    fig_width: 5
  word_document:
    fig_height: 3
    fig_width: 5
---


```{r, include=FALSE}
library(tidyverse)
library(knitr)
opts_chunk$set(
  tidy=FALSE,     # display code as typed
  size="small"    # slightly smaller font for code
)
```

## Introduction

This document is intended to provide you an opportunity to practice data wrangling using the `tidyverse`.

Let's begin by exploring the dataset of flights departing from New York City (NYC) airports in the year 2013.

```{r message = FALSE}
library(tidyverse)
library(nycflights13)
```

## Familiarizing ourselves with the dataset

What variables are included in the `flights` dataset?
How many rows are there?

```{r}
glimpse(flights)
```

SOLUTION: 


What variables are included in the `airports` dataset?
How many rows are there?

```{r}

```

SOLUTION: 

Which variables are included in the `airlines` dataset?
How many rows are there?

```{r}

```

SOLUTION: 


## Focusing on Atlanta

Let's focus on flights from NYC area airports to Atlanta GA (FAA code ATL).
Create a new object `atlanta` that includes only these flights (hint: use `filter()`).
How many flights to Atlanta were there in 2013?

```{r}
atlanta <- flights %>%
  filter(dest == "ATL")
glimpse(atlanta)
```

SOLUTION: 


## Seasonality

Is there a difference in the number of flights per month?  
Summarize the number of flights for each month and provide a sorted list with the months with the most flights first (hint: use `group_by()` in combination with `summarize()`).

```{r}
atlanta %>%
  group_by(month) %>%
  summarize(num_flights = n()) %>%
  arrange(desc(num_flights))
```

The most flights occurred during ...

## Which airlines

Which airlines flew to Atlanta and how often?
(Hint: use `left_join()` to make the carrier name more descriptive.)


```{r}

```



## Which airports

Which airports had flights that flew to Atlanta and how often?
(Hint: use `left_join()` to make the airport name more descriptive.)


```{r}

```

SOLUTION:

## Flight delays

What is the average arrival delay (in minutes) by airline?
(Hint: many flights are missing this information, so you will need to include the `na.rm = TRUE` option to the call to the `mean()` function.)


```{r}

```

SOLUTION:

## Challenge

Can you find an interesting insight about flights from NYC area airports to Atlanta during 2013?