HDS 2.1-2.2

Author

Cheyanne Bunnell

Loading R Packages

To begin, copy these two lines (without the number sign) to the console and run them, one at a time:

#install.packages("devtools")
#devtools::install_github("hellodata-science/hellodatascience")

This will install the hellodatascience package (be patient). You will also need to install the tidyverse and nycflights23 packages the ordinary way (again, in the console, without the #):

#install.packages("tidyverse")
#install.packages("nycflights23")

Now you can load the packages you just installed. Insert the code for loading them here:

library(devtools)
library(hellodatascience)
library(tidyverse)
library(nycflights23)

Data Frames

Read Section 2.1 of Hello Data Science. In that section, you found that the planets data has 8 rows and 7 columns. Note that I didn’t type the number of rows or columns; R calculated them and inserted them into my text. This is important because if the data changes (someone adds a row for Pluto, for example), I don’t have to change my text.

The flights data in the nycflights23 package gives on-time data for all flights scheduled to depart from one of the three New York City airports in 2023. Type ?flights in the console to see the help page. Write a sentence (like the one in the previous paragraph) that describes the number of rows and columns in the flights dataset by mixing R code into your sentence:

Getting to Know Data

Read Section 2.2 of Hello Data Science. Print the first few rows of the flights data (you certainly don’t want to print them all!):

head(flights)

# A tibble: 6 × 19
   year month   day dep_time sched_dep_time dep_delay arr_time sched_arr_time
  <int> <int> <int>    <int>          <int>     <dbl>    <int>          <int>
1  2023     1     1        1           2038       203      328              3
2  2023     1     1       18           2300        78      228            135
3  2023     1     1       31           2344        47      500            426
4  2023     1     1       33           2140       173      238           2352
5  2023     1     1       36           2048       228      223           2252
6  2023     1     1      503            500         3      808            815
# ℹ 11 more variables: arr_delay <dbl>, carrier <chr>, flight <int>,
#   tailnum <chr>, origin <chr>, dest <chr>, air_time <dbl>, distance <dbl>,
#   hour <dbl>, minute <dbl>, time_hour <dttm>

Use the glimpse function to get to know the variables in the flights data:

glimpse(flights)

Rows: 435,352
Columns: 19
$ year           <int> 2023, 2023, 2023, 2023, 2023, 2023, 2023, 2023, 2023, 2…
$ month          <int> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1…
$ day            <int> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1…
$ dep_time       <int> 1, 18, 31, 33, 36, 503, 520, 524, 537, 547, 549, 551, 5…
$ sched_dep_time <int> 2038, 2300, 2344, 2140, 2048, 500, 510, 530, 520, 545, …
$ dep_delay      <dbl> 203, 78, 47, 173, 228, 3, 10, -6, 17, 2, -10, -9, -7, -…
$ arr_time       <int> 328, 228, 500, 238, 223, 808, 948, 645, 926, 845, 905, …
$ sched_arr_time <int> 3, 135, 426, 2352, 2252, 815, 949, 710, 818, 852, 901, …
$ arr_delay      <dbl> 205, 53, 34, 166, 211, -7, -1, -25, 68, -7, 4, -13, -14…
$ carrier        <chr> "UA", "DL", "B6", "B6", "UA", "AA", "B6", "AA", "UA", "…
$ flight         <int> 628, 393, 371, 1053, 219, 499, 996, 981, 206, 225, 800,…
$ tailnum        <chr> "N25201", "N830DN", "N807JB", "N265JB", "N17730", "N925…
$ origin         <chr> "EWR", "JFK", "JFK", "JFK", "EWR", "EWR", "JFK", "EWR",…
$ dest           <chr> "SMF", "ATL", "BQN", "CHS", "DTW", "MIA", "BQN", "ORD",…
$ air_time       <dbl> 367, 108, 190, 108, 80, 154, 192, 119, 258, 157, 164, 1…
$ distance       <dbl> 2500, 760, 1576, 636, 488, 1085, 1576, 719, 1400, 1065,…
$ hour           <dbl> 20, 23, 23, 21, 20, 5, 5, 5, 5, 5, 5, 6, 5, 6, 6, 6, 6,…
$ minute         <dbl> 38, 0, 44, 40, 48, 0, 10, 30, 20, 45, 59, 0, 59, 0, 0, …
$ time_hour      <dttm> 2023-01-01 20:00:00, 2023-01-01 23:00:00, 2023-01-01 2…

Describe how these two functions are similar and how they differ:

They both give you a glance at the data. One is the first couple rows, they other switches the rows with the columns so you can focus on the table headers.