Introduction

This chapter will introduce you to data transformation using the dplyr package and a new dataset on flights that departed from New York City in 2013.

Prerequisites

# install.packages("nycflights13")

library(nycflights13)
library(tidyverse)

nycflights13

This dataset contains all 336,776 flights that departed from New York City in 2013. The data comes from the US Bureau of Transportation Statistics, and is documented in ?flights. For short:

 Data frame with columns year, month, day Date of departure.

 dep_time, arr_time Actual departure and arrival times (format HHMM or HMM), local tz.

 sched_dep_time, sched_arr_time Scheduled departure and arrival times (format HHMM or HMM), local tz.

flights

A tibble: 336776 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	9	30	2123	2125	-2	2223	2247	-24	EV	5489	N712EV	LGA	CHO	45	305	21	25	2013-09-30 21:00:00
2013	9	30	2127	2129	-2	2314	2323	-9	EV	3833	N16546	EWR	CLT	72	529	21	29	2013-09-30 21:00:00
2013	9	30	2128	2130	-2	2328	2359	-31	B6	97	N807JB	JFK	DEN	213	1626	21	30	2013-09-30 21:00:00
2013	9	30	2129	2059	30	2230	2232	-2	EV	5048	N751EV	LGA	RIC	45	292	20	59	2013-09-30 20:00:00
2013	9	30	2131	2140	-9	2225	2255	-30	MQ	3621	N807MQ	JFK	DCA	36	213	21	40	2013-09-30 21:00:00
2013	9	30	2140	2140	0	10	40	-30	AA	185	N335AA	JFK	LAX	298	2475	21	40	2013-09-30 21:00:00
2013	9	30	2142	2129	13	2250	2239	11	EV	4509	N12957	EWR	PWM	47	284	21	29	2013-09-30 21:00:00
2013	9	30	2145	2145	0	115	140	-25	B6	1103	N633JB	JFK	SJU	192	1598	21	45	2013-09-30 21:00:00
2013	9	30	2147	2137	10	30	27	3	B6	1371	N627JB	LGA	FLL	139	1076	21	37	2013-09-30 21:00:00
2013	9	30	2149	2156	-7	2245	2308	-23	UA	523	N813UA	EWR	BOS	37	200	21	56	2013-09-30 21:00:00
2013	9	30	2150	2159	-9	2250	2306	-16	EV	3842	N10575	EWR	MHT	39	209	21	59	2013-09-30 21:00:00
2013	9	30	2159	1845	194	2344	2030	194	9E	3320	N906XJ	JFK	BUF	50	301	18	45	2013-09-30 18:00:00
2013	9	30	2203	2205	-2	2339	2331	8	EV	5311	N722EV	LGA	BGR	61	378	22	5	2013-09-30 22:00:00
2013	9	30	2207	2140	27	2257	2250	7	MQ	3660	N532MQ	LGA	BNA	97	764	21	40	2013-09-30 21:00:00
2013	9	30	2211	2059	72	2339	2242	57	EV	4672	N12145	EWR	STL	120	872	20	59	2013-09-30 20:00:00
2013	9	30	2231	2245	-14	2335	2356	-21	B6	108	N193JB	JFK	PWM	48	273	22	45	2013-09-30 22:00:00
2013	9	30	2233	2113	80	112	30	42	UA	471	N578UA	EWR	SFO	318	2565	21	13	2013-09-30 21:00:00
2013	9	30	2235	2001	154	59	2249	130	B6	1083	N804JB	JFK	MCO	123	944	20	1	2013-09-30 20:00:00
2013	9	30	2237	2245	-8	2345	2353	-8	B6	234	N318JB	JFK	BTV	43	266	22	45	2013-09-30 22:00:00
2013	9	30	2240	2245	-5	2334	2351	-17	B6	1816	N354JB	JFK	SYR	41	209	22	45	2013-09-30 22:00:00
2013	9	30	2240	2250	-10	2347	7	-20	B6	2002	N281JB	JFK	BUF	52	301	22	50	2013-09-30 22:00:00
2013	9	30	2241	2246	-5	2345	1	-16	B6	486	N346JB	JFK	ROC	47	264	22	46	2013-09-30 22:00:00
2013	9	30	2307	2255	12	2359	2358	1	B6	718	N565JB	JFK	BOS	33	187	22	55	2013-09-30 22:00:00
2013	9	30	2349	2359	-10	325	350	-25	B6	745	N516JB	JFK	PSE	196	1617	23	59	2013-09-30 23:00:00
2013	9	30	NA	1842	NA	NA	2019	NA	EV	5274	N740EV	LGA	BNA	NA	764	18	42	2013-09-30 18:00:00
2013	9	30	NA	1455	NA	NA	1634	NA	9E	3393	NA	JFK	DCA	NA	213	14	55	2013-09-30 14:00:00
2013	9	30	NA	2200	NA	NA	2312	NA	9E	3525	NA	LGA	SYR	NA	198	22	0	2013-09-30 22:00:00
2013	9	30	NA	1210	NA	NA	1330	NA	MQ	3461	N535MQ	LGA	BNA	NA	764	12	10	2013-09-30 12:00:00
2013	9	30	NA	1159	NA	NA	1344	NA	MQ	3572	N511MQ	LGA	CLE	NA	419	11	59	2013-09-30 11:00:00
2013	9	30	NA	840	NA	NA	1020	NA	MQ	3531	N839MQ	LGA	RDU	NA	431	8	40	2013-09-30 08:00:00

glimpse(flights)

Rows: 336,776
Columns: 19
$ year           [3m[90m<int>[39m[23m 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2~
$ month          [3m[90m<int>[39m[23m 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1~
$ day            [3m[90m<int>[39m[23m 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1~
$ dep_time       [3m[90m<int>[39m[23m 517, 533, 542, 544, 554, 554, 555, 557, 557, 558, 558, ~
$ sched_dep_time [3m[90m<int>[39m[23m 515, 529, 540, 545, 600, 558, 600, 600, 600, 600, 600, ~
$ dep_delay      [3m[90m<dbl>[39m[23m 2, 4, 2, -1, -6, -4, -5, -3, -3, -2, -2, -2, -2, -2, -1~
$ arr_time       [3m[90m<int>[39m[23m 830, 850, 923, 1004, 812, 740, 913, 709, 838, 753, 849,~
$ sched_arr_time [3m[90m<int>[39m[23m 819, 830, 850, 1022, 837, 728, 854, 723, 846, 745, 851,~
$ arr_delay      [3m[90m<dbl>[39m[23m 11, 20, 33, -18, -25, 12, 19, -14, -8, 8, -2, -3, 7, -1~
$ carrier        [3m[90m<chr>[39m[23m "UA", "UA", "AA", "B6", "DL", "UA", "B6", "EV", "B6", "~
$ flight         [3m[90m<int>[39m[23m 1545, 1714, 1141, 725, 461, 1696, 507, 5708, 79, 301, 4~
$ tailnum        [3m[90m<chr>[39m[23m "N14228", "N24211", "N619AA", "N804JB", "N668DN", "N394~
$ origin         [3m[90m<chr>[39m[23m "EWR", "LGA", "JFK", "JFK", "LGA", "EWR", "EWR", "LGA",~
$ dest           [3m[90m<chr>[39m[23m "IAH", "IAH", "MIA", "BQN", "ATL", "ORD", "FLL", "IAD",~
$ air_time       [3m[90m<dbl>[39m[23m 227, 227, 160, 183, 116, 150, 158, 53, 140, 138, 149, 1~
$ distance       [3m[90m<dbl>[39m[23m 1400, 1416, 1089, 1576, 762, 719, 1065, 229, 944, 733, ~
$ hour           [3m[90m<dbl>[39m[23m 5, 5, 5, 5, 6, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 6, 6, 6~
$ minute         [3m[90m<dbl>[39m[23m 15, 29, 40, 45, 0, 58, 0, 0, 0, 0, 0, 0, 0, 0, 0, 59, 0~
$ time_hour      [3m[90m<dttm>[39m[23m 2013-01-01 05:00:00, 2013-01-01 05:00:00, 2013-01-01 0~

`dplyr` basics

The first argument is always a data frame.
The subsequent arguments typically describe which columns to operate on, using the variable names (without quotes).
The output is always a new data frame.

|>: the pipe to combining multiple verbs (functions): the pipe takes the thing on its left and passes it along to the function on its right so that x |> f(y) is equivalent to f(x, y), and x |> f(y) |> g(z) is equivalent to g(f(x, y), z). The easiest way to pronounce the pipe is “then”.

dplyr’s verbs are organized into four groups based on what they operate on: rows, columns, groups, or tables. In the following sections you’ll learn the most important verbs for rows, columns, and groups, then we’ll come back to the join verbs that work on tables in Chapter 19.

# |>: the pipe to combining multiple verbs (functions)
flights |>
  filter(dest == "IAH") |> 
  group_by(year, month, day) |> 
  summarize(
    arr_delay = mean(arr_delay, na.rm = TRUE)
  )

[1m[22m`summarise()` has grouped output by 'year', 'month'. You can override using the
`.groups` argument.

A grouped_df: 365 x 4
year	month	day	arr_delay
<int>	<int>	<int>	<dbl>
2013	1	1	17.850000
2013	1	2	7.000000
2013	1	3	18.315789
2013	1	4	-3.200000
2013	1	5	20.230769
2013	1	6	9.277778
2013	1	7	-7.736842
2013	1	8	7.789474
2013	1	9	18.055556
2013	1	10	6.684211
2013	1	11	-22.526316
2013	1	12	-19.923077
2013	1	13	14.833333
2013	1	14	17.421053
2013	1	15	26.105263
2013	1	16	40.105263
2013	1	17	-7.894737
2013	1	18	-5.210526
2013	1	19	2.153846
2013	1	20	10.352941
2013	1	21	19.789474
2013	1	22	-5.055556
2013	1	23	-6.947368
2013	1	24	-15.894737
2013	1	25	-10.368421
2013	1	26	-8.384615
2013	1	27	-16.055556
2013	1	28	-15.157895
2013	1	29	-20.842105
2013	1	30	20.842105
...	...	...	...
2013	12	2	-6.5000000
2013	12	3	-8.4545455
2013	12	4	-3.1363636
2013	12	5	51.7142857
2013	12	6	14.8181818
2013	12	7	18.8666667
2013	12	8	29.4705882
2013	12	9	34.5454545
2013	12	10	60.3529412
2013	12	11	3.4090909
2013	12	12	5.3333333
2013	12	13	-3.0000000
2013	12	14	54.6666667
2013	12	15	6.6470588
2013	12	16	-8.1818182
2013	12	17	33.4500000
2013	12	18	8.4090909
2013	12	19	-6.6190476
2013	12	20	20.1000000
2013	12	21	50.1250000
2013	12	22	28.3333333
2013	12	23	28.8181818
2013	12	24	2.3125000
2013	12	25	7.5833333
2013	12	26	-0.4444444
2013	12	27	6.1666667
2013	12	28	9.5000000
2013	12	29	23.6111111
2013	12	30	23.6842105
2013	12	31	-4.9333333

Rows

Some important verbs that operate on rows:

filter(): allows you to keep rows based on the values of the columns without changing their order
arrange(): changes the order of the rows based on the value of the columns (without changing which are present)

Both functions only affect the rows, and the columns are left unchanged.

distinct() which finds rows with unique values but unlike arrange() and filter() it can also optionally modify the columns.

`filter()`

flights |> filter(dep_delay > 1000)

A tibble: 5 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	9	641	900	1301	1242	1530	1272	HA	51	N384HA	JFK	HNL	640	4983	9	0	2013-01-09 09:00:00
2013	1	10	1121	1635	1126	1239	1810	1109	MQ	3695	N517MQ	EWR	ORD	111	719	16	35	2013-01-10 16:00:00
2013	6	15	1432	1935	1137	1607	2120	1127	MQ	3535	N504MQ	JFK	CMH	74	483	19	35	2013-06-15 19:00:00
2013	7	22	845	1600	1005	1044	1815	989	MQ	3075	N665MQ	JFK	CVG	96	589	16	0	2013-07-22 16:00:00
2013	9	20	1139	1845	1014	1457	2210	1007	AA	177	N338AA	JFK	SFO	354	2586	18	45	2013-09-20 18:00:00

# Flights that departed on January 1
flights |> filter(month==1 & day==1)

A tibble: 842 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	1	1	2140	2135	5	210	224	-14	B6	701	N284JB	JFK	SJU	189	1598	21	35	2013-01-01 21:00:00
2013	1	1	2157	2155	2	43	41	2	B6	43	N537JB	JFK	MCO	140	944	21	55	2013-01-01 21:00:00
2013	1	1	2158	2200	-2	2254	2307	-13	EV	4103	N14998	EWR	BWI	36	169	22	0	2013-01-01 22:00:00
2013	1	1	2205	1720	285	46	2040	246	AA	1999	N5DNAA	EWR	MIA	146	1085	17	20	2013-01-01 17:00:00
2013	1	1	2209	2145	24	58	37	21	B6	35	N608JB	JFK	PBI	143	1028	21	45	2013-01-01 21:00:00
2013	1	1	2209	2155	14	2400	2337	23	B6	1109	N216JB	JFK	RDU	86	427	21	55	2013-01-01 21:00:00
2013	1	1	2211	2145	26	2339	2311	28	B6	104	N228JB	JFK	BUF	64	301	21	45	2013-01-01 21:00:00
2013	1	1	2217	2229	-12	249	315	-26	B6	713	N547JB	JFK	SJU	191	1598	22	29	2013-01-01 22:00:00
2013	1	1	2217	2130	47	140	27	73	B6	21	N516JB	JFK	TPA	163	1005	21	30	2013-01-01 21:00:00
2013	1	1	2221	2000	141	2331	2124	127	EV	4462	N13566	EWR	BUF	56	282	20	0	2013-01-01 20:00:00
2013	1	1	2224	2200	24	2324	2316	8	EV	4206	N16561	EWR	PWM	47	284	22	0	2013-01-01 22:00:00
2013	1	1	2229	2159	30	149	100	49	B6	11	N531JB	JFK	FLL	153	1069	21	59	2013-01-01 21:00:00
2013	1	1	2240	2245	-5	2340	2356	-16	B6	608	N279JB	JFK	PWM	44	273	22	45	2013-01-01 22:00:00
2013	1	1	2250	2255	-5	2352	2359	-7	B6	1018	N521JB	JFK	BOS	37	187	22	55	2013-01-01 22:00:00
2013	1	1	2302	2200	62	2342	2253	49	EV	4276	N13903	EWR	BDL	24	116	22	0	2013-01-01 22:00:00
2013	1	1	2306	2245	21	28	5	23	B6	30	N281JB	JFK	ROC	59	264	22	45	2013-01-01 22:00:00
2013	1	1	2307	2245	22	32	2357	35	B6	128	N178JB	JFK	BTV	59	266	22	45	2013-01-01 22:00:00
2013	1	1	2310	2255	15	24	15	9	B6	112	N646JB	JFK	BUF	57	301	22	55	2013-01-01 22:00:00
2013	1	1	2312	2000	192	21	2110	191	EV	4312	N13958	EWR	DCA	44	199	20	0	2013-01-01 20:00:00
2013	1	1	2323	2200	83	22	2313	69	EV	4257	N13538	EWR	BTV	44	266	22	0	2013-01-01 22:00:00
2013	1	1	2326	2130	116	131	18	73	B6	199	N594JB	JFK	LAS	290	2248	21	30	2013-01-01 21:00:00
2013	1	1	2327	2250	37	32	2359	33	B6	22	N639JB	JFK	SYR	45	209	22	50	2013-01-01 22:00:00
2013	1	1	2343	1724	379	314	1938	456	EV	4321	N21197	EWR	MCI	222	1092	17	24	2013-01-01 17:00:00
2013	1	1	2353	2359	-6	425	445	-20	B6	739	N591JB	JFK	PSE	195	1617	23	59	2013-01-01 23:00:00
2013	1	1	2353	2359	-6	418	442	-24	B6	707	N794JB	JFK	SJU	185	1598	23	59	2013-01-01 23:00:00
2013	1	1	2356	2359	-3	425	437	-12	B6	727	N588JB	JFK	BQN	186	1576	23	59	2013-01-01 23:00:00
2013	1	1	NA	1630	NA	NA	1815	NA	EV	4308	N18120	EWR	RDU	NA	416	16	30	2013-01-01 16:00:00
2013	1	1	NA	1935	NA	NA	2240	NA	AA	791	N3EHAA	LGA	DFW	NA	1389	19	35	2013-01-01 19:00:00
2013	1	1	NA	1500	NA	NA	1825	NA	AA	1925	N3EVAA	LGA	MIA	NA	1096	15	0	2013-01-01 15:00:00
2013	1	1	NA	600	NA	NA	901	NA	B6	125	N618JB	JFK	FLL	NA	1069	6	0	2013-01-01 06:00:00

# A shorter way to select flights that departed in January or February
flights |> 
  filter(month %in% c(1, 2))
  # the same as filter(month==1 | month==2)
  # but not filter(month == 1 | 2) - error!

A tibble: 51955 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	2	28	2157	2007	110	2344	2206	98	EV	4572	N29906	EWR	GSP	93	594	20	7	2013-02-28 20:00:00
2013	2	28	2158	1910	168	19	2215	124	AA	2075	N4YSAA	EWR	DFW	182	1372	19	10	2013-02-28 19:00:00
2013	2	28	2158	2145	13	49	34	15	B6	35	N708JB	JFK	PBI	151	1028	21	45	2013-02-28 21:00:00
2013	2	28	2201	2155	6	59	41	18	B6	43	N579JB	JFK	MCO	149	944	21	55	2013-02-28 21:00:00
2013	2	28	2205	2045	80	2304	2216	48	9E	3395	N916XJ	JFK	DCA	38	213	20	45	2013-02-28 20:00:00
2013	2	28	2205	2159	6	106	56	10	B6	11	N554JB	JFK	FLL	158	1069	21	59	2013-02-28 21:00:00
2013	2	28	2218	2150	28	115	42	33	B6	325	N504JB	JFK	TPA	154	1005	21	50	2013-02-28 21:00:00
2013	2	28	2223	2023	120	252	114	98	UA	1071	N37298	EWR	BQN	188	1585	20	23	2013-02-28 20:00:00
2013	2	28	2226	2029	117	115	2333	102	UA	771	N560UA	JFK	LAX	313	2475	20	29	2013-02-28 20:00:00
2013	2	28	2229	2230	-1	258	312	-14	B6	713	N523JB	JFK	SJU	193	1598	22	30	2013-02-28 22:00:00
2013	2	28	2239	2245	-6	2339	2354	-15	B6	608	N197JB	JFK	PWM	44	273	22	45	2013-02-28 22:00:00
2013	2	28	2242	2250	-8	2350	5	-15	B6	30	N351JB	JFK	ROC	51	264	22	50	2013-02-28 22:00:00
2013	2	28	2245	2245	0	5	2356	9	B6	128	N184JB	JFK	BTV	48	266	22	45	2013-02-28 22:00:00
2013	2	28	2254	2258	-4	10	19	-9	B6	112	N655JB	JFK	BUF	53	301	22	58	2013-02-28 22:00:00
2013	2	28	2257	2140	77	2338	2241	57	EV	4276	N12567	EWR	BDL	24	116	21	40	2013-02-28 21:00:00
2013	2	28	2257	2255	2	2400	2357	3	B6	1018	N807JB	JFK	BOS	35	187	22	55	2013-02-28 22:00:00
2013	2	28	2323	2251	32	18	2357	21	B6	22	N279JB	JFK	SYR	40	209	22	51	2013-02-28 22:00:00
2013	2	28	2342	2352	-10	413	437	-24	B6	739	N656JB	JFK	PSE	193	1617	23	52	2013-02-28 23:00:00
2013	2	28	2356	2358	-2	423	438	-15	B6	707	N646JB	JFK	SJU	192	1598	23	58	2013-02-28 23:00:00
2013	2	28	2359	2359	0	443	438	5	B6	727	N641JB	JFK	BQN	192	1576	23	59	2013-02-28 23:00:00
2013	2	28	NA	600	NA	NA	722	NA	EV	5739	N833AS	LGA	IAD	NA	229	6	0	2013-02-28 06:00:00
2013	2	28	NA	1820	NA	NA	2003	NA	EV	5409	N740EV	LGA	MSN	NA	812	18	20	2013-02-28 18:00:00
2013	2	28	NA	1154	NA	NA	1447	NA	B6	27	N274JB	JFK	TPA	NA	1005	11	54	2013-02-28 11:00:00
2013	2	28	NA	900	NA	NA	1020	NA	US	2120	NA	LGA	BOS	NA	184	9	0	2013-02-28 09:00:00
2013	2	28	NA	605	NA	NA	805	NA	MQ	4401	N730MQ	LGA	DTW	NA	502	6	5	2013-02-28 06:00:00
2013	2	28	NA	850	NA	NA	1035	NA	MQ	4558	N737MQ	LGA	CLE	NA	419	8	50	2013-02-28 08:00:00
2013	2	28	NA	905	NA	NA	1115	NA	MQ	4478	N722MQ	LGA	DTW	NA	502	9	5	2013-02-28 09:00:00
2013	2	28	NA	1115	NA	NA	1310	NA	MQ	4485	N725MQ	LGA	CMH	NA	479	11	15	2013-02-28 11:00:00
2013	2	28	NA	830	NA	NA	1205	NA	UA	1480	NA	EWR	SFO	NA	2565	8	30	2013-02-28 08:00:00
2013	2	28	NA	840	NA	NA	1147	NA	UA	443	NA	JFK	LAX	NA	2475	8	40	2013-02-28 08:00:00

`arrange()`

flights |> arrange(year, month, day, dep_time)

A tibble: 336776 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	12	31	2155	2039	76	253	2355	NA	B6	1205	N627JB	JFK	PDX	NA	2454	20	39	2013-12-31 20:00:00
2013	12	31	2155	2150	5	110	51	19	B6	1901	N729JB	JFK	FLL	164	1069	21	50	2013-12-31 21:00:00
2013	12	31	2159	2155	4	55	46	9	B6	2053	N593JB	JFK	PBI	155	1028	21	55	2013-12-31 21:00:00
2013	12	31	2206	2110	56	44	2339	65	B6	775	N184JB	JFK	MSY	195	1182	21	10	2013-12-31 21:00:00
2013	12	31	2211	2159	12	100	45	15	B6	1183	N715JB	JFK	MCO	148	944	21	59	2013-12-31 21:00:00
2013	12	31	2218	2219	-1	315	304	11	B6	1203	N625JB	JFK	SJU	202	1598	22	19	2013-12-31 22:00:00
2013	12	31	2235	2245	-10	2351	2355	-4	B6	234	N355JB	JFK	BTV	49	266	22	45	2013-12-31 22:00:00
2013	12	31	2245	2250	-5	2359	2356	3	B6	1816	N318JB	JFK	SYR	51	209	22	50	2013-12-31 22:00:00
2013	12	31	2310	2255	15	7	2356	11	B6	718	N279JB	JFK	BOS	40	187	22	55	2013-12-31 22:00:00
2013	12	31	2321	2250	31	46	8	38	B6	2002	N179JB	JFK	BUF	66	301	22	50	2013-12-31 22:00:00
2013	12	31	2328	2330	-2	412	409	3	B6	1389	N651JB	EWR	SJU	198	1608	23	30	2013-12-31 23:00:00
2013	12	31	2332	2245	47	58	3	55	B6	486	N334JB	JFK	ROC	60	264	22	45	2013-12-31 22:00:00
2013	12	31	2355	2359	-4	430	440	-10	B6	1503	N509JB	JFK	SJU	195	1598	23	59	2013-12-31 23:00:00
2013	12	31	2356	2359	-3	436	445	-9	B6	745	N665JB	JFK	PSE	200	1617	23	59	2013-12-31 23:00:00
2013	12	31	NA	1520	NA	NA	1705	NA	AA	341	N568AA	LGA	ORD	NA	733	15	20	2013-12-31 15:00:00
2013	12	31	NA	2025	NA	NA	2205	NA	AA	371	N482AA	LGA	ORD	NA	733	20	25	2013-12-31 20:00:00
2013	12	31	NA	1932	NA	NA	2305	NA	B6	161	N516JB	JFK	SMF	NA	2521	19	32	2013-12-31 19:00:00
2013	12	31	NA	1505	NA	NA	1725	NA	EV	4181	N24103	EWR	MCI	NA	1092	15	5	2013-12-31 15:00:00
2013	12	31	NA	1000	NA	NA	1252	NA	UA	1124	NA	EWR	EGE	NA	1725	10	0	2013-12-31 10:00:00
2013	12	31	NA	840	NA	NA	1205	NA	UA	1151	NA	EWR	SEA	NA	2402	8	40	2013-12-31 08:00:00
2013	12	31	NA	754	NA	NA	1118	NA	UA	1455	NA	EWR	LAX	NA	2454	7	54	2013-12-31 07:00:00
2013	12	31	NA	2000	NA	NA	2146	NA	UA	1482	NA	EWR	ORD	NA	719	20	0	2013-12-31 20:00:00
2013	12	31	NA	1500	NA	NA	1817	NA	UA	1483	NA	EWR	AUS	NA	1504	15	0	2013-12-31 15:00:00
2013	12	31	NA	1430	NA	NA	1750	NA	UA	1493	NA	EWR	LAX	NA	2454	14	30	2013-12-31 14:00:00
2013	12	31	NA	855	NA	NA	1142	NA	UA	1506	NA	EWR	JAC	NA	1874	8	55	2013-12-31 08:00:00
2013	12	31	NA	705	NA	NA	931	NA	UA	1729	NA	EWR	DEN	NA	1605	7	5	2013-12-31 07:00:00
2013	12	31	NA	825	NA	NA	1029	NA	US	1831	NA	JFK	CLT	NA	541	8	25	2013-12-31 08:00:00
2013	12	31	NA	1615	NA	NA	1800	NA	MQ	3301	N844MQ	LGA	RDU	NA	431	16	15	2013-12-31 16:00:00
2013	12	31	NA	600	NA	NA	735	NA	UA	219	NA	EWR	ORD	NA	719	6	0	2013-12-31 06:00:00
2013	12	31	NA	830	NA	NA	1154	NA	UA	443	NA	JFK	LAX	NA	2475	8	30	2013-12-31 08:00:00

flights |> arrange(desc(dep_delay))

A tibble: 336776 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	9	641	900	1301	1242	1530	1272	HA	51	N384HA	JFK	HNL	640	4983	9	0	2013-01-09 09:00:00
2013	6	15	1432	1935	1137	1607	2120	1127	MQ	3535	N504MQ	JFK	CMH	74	483	19	35	2013-06-15 19:00:00
2013	1	10	1121	1635	1126	1239	1810	1109	MQ	3695	N517MQ	EWR	ORD	111	719	16	35	2013-01-10 16:00:00
2013	9	20	1139	1845	1014	1457	2210	1007	AA	177	N338AA	JFK	SFO	354	2586	18	45	2013-09-20 18:00:00
2013	7	22	845	1600	1005	1044	1815	989	MQ	3075	N665MQ	JFK	CVG	96	589	16	0	2013-07-22 16:00:00
2013	4	10	1100	1900	960	1342	2211	931	DL	2391	N959DL	JFK	TPA	139	1005	19	0	2013-04-10 19:00:00
2013	3	17	2321	810	911	135	1020	915	DL	2119	N927DA	LGA	MSP	167	1020	8	10	2013-03-17 08:00:00
2013	6	27	959	1900	899	1236	2226	850	DL	2007	N3762Y	JFK	PDX	313	2454	19	0	2013-06-27 19:00:00
2013	7	22	2257	759	898	121	1026	895	DL	2047	N6716C	LGA	ATL	109	762	7	59	2013-07-22 07:00:00
2013	12	5	756	1700	896	1058	2020	878	AA	172	N5DMAA	EWR	MIA	149	1085	17	0	2013-12-05 17:00:00
2013	5	3	1133	2055	878	1250	2215	875	MQ	3744	N523MQ	EWR	ORD	112	719	20	55	2013-05-03 20:00:00
2013	1	1	848	1835	853	1001	1950	851	MQ	3944	N942MQ	JFK	BWI	41	184	18	35	2013-01-01 18:00:00
2013	2	10	2243	830	853	100	1106	834	F9	835	N203FR	LGA	DEN	233	1620	8	30	2013-02-10 08:00:00
2013	5	19	713	1700	853	1007	1955	852	AA	257	N3HEAA	JFK	LAS	323	2248	17	0	2013-05-19 17:00:00
2013	12	19	734	1725	849	1046	2039	847	DL	1223	N375NC	EWR	SLC	290	1969	17	25	2013-12-19 17:00:00
2013	12	17	705	1700	845	1026	2020	846	AA	172	N5EMAA	EWR	MIA	145	1085	17	0	2013-12-17 17:00:00
2013	12	14	830	1845	825	1210	2154	856	DL	2391	N939DL	JFK	TPA	173	1005	18	45	2013-12-14 18:00:00
2013	4	19	912	1940	812	1228	2247	821	DL	1435	N900DE	LGA	TPA	174	1010	19	40	2013-04-19 19:00:00
2013	6	27	753	1830	803	937	2015	802	AA	2019	N571AA	LGA	STL	134	888	18	30	2013-06-27 18:00:00
2013	3	18	1020	2100	800	1336	32	784	DL	2363	N624AG	JFK	LAX	335	2475	21	0	2013-03-18 21:00:00
2013	11	3	603	1645	798	829	1913	796	DL	2042	N990AT	EWR	ATL	109	746	16	45	2013-11-03 16:00:00
2013	4	19	617	1700	797	858	1955	783	AA	257	N3GJAA	JFK	LAS	313	2248	17	0	2013-04-19 17:00:00
2013	6	27	615	1705	790	853	2004	769	DL	503	N372DA	JFK	SAN	312	2446	17	5	2013-06-27 17:00:00
2013	2	19	2324	1016	788	114	1227	767	DL	2319	N324US	LGA	MSP	136	1020	10	16	2013-02-19 10:00:00
2013	6	27	732	1825	787	932	2032	780	DL	1715	N335NB	LGA	MSY	160	1183	18	25	2013-06-27 18:00:00
2013	2	24	1921	615	786	2135	842	773	DL	575	N348NW	EWR	ATL	111	746	6	15	2013-02-24 06:00:00
2013	4	19	606	1725	761	923	2020	783	AA	1901	N3DGAA	JFK	IAH	222	1417	17	25	2013-04-19 17:00:00
2013	4	19	758	1925	753	1049	2225	744	DL	1485	N927DA	LGA	MCO	149	950	19	25	2013-04-19 19:00:00
2013	2	16	757	1930	747	1013	2149	744	9E	3798	N8940E	JFK	CLT	85	541	19	30	2013-02-16 19:00:00
2013	10	14	2042	900	702	2255	1127	688	DL	502	N943DL	EWR	ATL	98	746	9	0	2013-10-14 09:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	9	24	NA	1625	NA	NA	1750	NA	MQ	3622	N524MQ	LGA	BNA	NA	764	16	25	2013-09-24 16:00:00
2013	9	25	NA	1259	NA	NA	1507	NA	EV	5207	N615QX	LGA	CLT	NA	544	12	59	2013-09-25 12:00:00
2013	9	25	NA	845	NA	NA	1018	NA	EV	5286	N615QX	LGA	BTV	NA	258	8	45	2013-09-25 08:00:00
2013	9	25	NA	1755	NA	NA	1932	NA	EV	5287	N722EV	LGA	MSN	NA	812	17	55	2013-09-25 17:00:00
2013	9	25	NA	600	NA	NA	716	NA	EV	5716	N877AS	JFK	IAD	NA	228	6	0	2013-09-25 06:00:00
2013	9	25	NA	836	NA	NA	944	NA	B6	2280	N258JB	EWR	BOS	NA	200	8	36	2013-09-25 08:00:00
2013	9	25	NA	1300	NA	NA	1409	NA	US	2148	NA	LGA	BOS	NA	184	13	0	2013-09-25 13:00:00
2013	9	25	NA	1900	NA	NA	2014	NA	US	2160	NA	LGA	BOS	NA	184	19	0	2013-09-25 19:00:00
2013	9	25	NA	1300	NA	NA	1450	NA	MQ	3388	N817MQ	LGA	CMH	NA	479	13	0	2013-09-25 13:00:00
2013	9	25	NA	1655	NA	NA	1840	NA	MQ	3411	N735MQ	LGA	RDU	NA	431	16	55	2013-09-25 16:00:00
2013	9	25	NA	1559	NA	NA	1719	NA	MQ	3748	N530MQ	EWR	ORD	NA	719	15	59	2013-09-25 15:00:00
2013	9	26	NA	915	NA	NA	1141	NA	EV	5109	N748EV	LGA	CHS	NA	641	9	15	2013-09-26 09:00:00
2013	9	26	NA	1400	NA	NA	1512	NA	US	2183	NA	LGA	DCA	NA	214	14	0	2013-09-26 14:00:00
2013	9	26	NA	1240	NA	NA	1525	NA	WN	4720	N691WN	EWR	HOU	NA	1411	12	40	2013-09-26 12:00:00
2013	9	27	NA	600	NA	NA	730	NA	AA	301	N584AA	LGA	ORD	NA	733	6	0	2013-09-27 06:00:00
2013	9	27	NA	2100	NA	NA	2211	NA	US	2164	NA	LGA	BOS	NA	184	21	0	2013-09-27 21:00:00
2013	9	27	NA	1329	NA	NA	1444	NA	MQ	3760	N505MQ	EWR	ORD	NA	719	13	29	2013-09-27 13:00:00
2013	9	27	NA	1600	NA	NA	1739	NA	UA	269	NA	LGA	ORD	NA	733	16	0	2013-09-27 16:00:00
2013	9	28	NA	1803	NA	NA	1927	NA	EV	5563	N724EV	LGA	BTV	NA	258	18	3	2013-09-28 18:00:00
2013	9	28	NA	910	NA	NA	1220	NA	AA	1	N320AA	JFK	LAX	NA	2475	9	10	2013-09-28 09:00:00
2013	9	28	NA	1635	NA	NA	1827	NA	US	581	NA	EWR	CLT	NA	529	16	35	2013-09-28 16:00:00
2013	9	29	NA	2054	NA	NA	2302	NA	EV	4536	N13988	EWR	CVG	NA	569	20	54	2013-09-29 20:00:00
2013	9	29	NA	1830	NA	NA	2010	NA	MQ	3134	N508MQ	EWR	ORD	NA	719	18	30	2013-09-29 18:00:00
2013	9	29	NA	700	NA	NA	833	NA	UA	331	NA	LGA	ORD	NA	733	7	0	2013-09-29 07:00:00
2013	9	30	NA	1842	NA	NA	2019	NA	EV	5274	N740EV	LGA	BNA	NA	764	18	42	2013-09-30 18:00:00
2013	9	30	NA	1455	NA	NA	1634	NA	9E	3393	NA	JFK	DCA	NA	213	14	55	2013-09-30 14:00:00
2013	9	30	NA	2200	NA	NA	2312	NA	9E	3525	NA	LGA	SYR	NA	198	22	0	2013-09-30 22:00:00
2013	9	30	NA	1210	NA	NA	1330	NA	MQ	3461	N535MQ	LGA	BNA	NA	764	12	10	2013-09-30 12:00:00
2013	9	30	NA	1159	NA	NA	1344	NA	MQ	3572	N511MQ	LGA	CLE	NA	419	11	59	2013-09-30 11:00:00
2013	9	30	NA	840	NA	NA	1020	NA	MQ	3531	N839MQ	LGA	RDU	NA	431	8	40	2013-09-30 08:00:00

`distinct()`

# Remove duplicate rows, if any
flights |> 
  distinct()

A tibble: 336776 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	9	30	2123	2125	-2	2223	2247	-24	EV	5489	N712EV	LGA	CHO	45	305	21	25	2013-09-30 21:00:00
2013	9	30	2127	2129	-2	2314	2323	-9	EV	3833	N16546	EWR	CLT	72	529	21	29	2013-09-30 21:00:00
2013	9	30	2128	2130	-2	2328	2359	-31	B6	97	N807JB	JFK	DEN	213	1626	21	30	2013-09-30 21:00:00
2013	9	30	2129	2059	30	2230	2232	-2	EV	5048	N751EV	LGA	RIC	45	292	20	59	2013-09-30 20:00:00
2013	9	30	2131	2140	-9	2225	2255	-30	MQ	3621	N807MQ	JFK	DCA	36	213	21	40	2013-09-30 21:00:00
2013	9	30	2140	2140	0	10	40	-30	AA	185	N335AA	JFK	LAX	298	2475	21	40	2013-09-30 21:00:00
2013	9	30	2142	2129	13	2250	2239	11	EV	4509	N12957	EWR	PWM	47	284	21	29	2013-09-30 21:00:00
2013	9	30	2145	2145	0	115	140	-25	B6	1103	N633JB	JFK	SJU	192	1598	21	45	2013-09-30 21:00:00
2013	9	30	2147	2137	10	30	27	3	B6	1371	N627JB	LGA	FLL	139	1076	21	37	2013-09-30 21:00:00
2013	9	30	2149	2156	-7	2245	2308	-23	UA	523	N813UA	EWR	BOS	37	200	21	56	2013-09-30 21:00:00
2013	9	30	2150	2159	-9	2250	2306	-16	EV	3842	N10575	EWR	MHT	39	209	21	59	2013-09-30 21:00:00
2013	9	30	2159	1845	194	2344	2030	194	9E	3320	N906XJ	JFK	BUF	50	301	18	45	2013-09-30 18:00:00
2013	9	30	2203	2205	-2	2339	2331	8	EV	5311	N722EV	LGA	BGR	61	378	22	5	2013-09-30 22:00:00
2013	9	30	2207	2140	27	2257	2250	7	MQ	3660	N532MQ	LGA	BNA	97	764	21	40	2013-09-30 21:00:00
2013	9	30	2211	2059	72	2339	2242	57	EV	4672	N12145	EWR	STL	120	872	20	59	2013-09-30 20:00:00
2013	9	30	2231	2245	-14	2335	2356	-21	B6	108	N193JB	JFK	PWM	48	273	22	45	2013-09-30 22:00:00
2013	9	30	2233	2113	80	112	30	42	UA	471	N578UA	EWR	SFO	318	2565	21	13	2013-09-30 21:00:00
2013	9	30	2235	2001	154	59	2249	130	B6	1083	N804JB	JFK	MCO	123	944	20	1	2013-09-30 20:00:00
2013	9	30	2237	2245	-8	2345	2353	-8	B6	234	N318JB	JFK	BTV	43	266	22	45	2013-09-30 22:00:00
2013	9	30	2240	2245	-5	2334	2351	-17	B6	1816	N354JB	JFK	SYR	41	209	22	45	2013-09-30 22:00:00
2013	9	30	2240	2250	-10	2347	7	-20	B6	2002	N281JB	JFK	BUF	52	301	22	50	2013-09-30 22:00:00
2013	9	30	2241	2246	-5	2345	1	-16	B6	486	N346JB	JFK	ROC	47	264	22	46	2013-09-30 22:00:00
2013	9	30	2307	2255	12	2359	2358	1	B6	718	N565JB	JFK	BOS	33	187	22	55	2013-09-30 22:00:00
2013	9	30	2349	2359	-10	325	350	-25	B6	745	N516JB	JFK	PSE	196	1617	23	59	2013-09-30 23:00:00
2013	9	30	NA	1842	NA	NA	2019	NA	EV	5274	N740EV	LGA	BNA	NA	764	18	42	2013-09-30 18:00:00
2013	9	30	NA	1455	NA	NA	1634	NA	9E	3393	NA	JFK	DCA	NA	213	14	55	2013-09-30 14:00:00
2013	9	30	NA	2200	NA	NA	2312	NA	9E	3525	NA	LGA	SYR	NA	198	22	0	2013-09-30 22:00:00
2013	9	30	NA	1210	NA	NA	1330	NA	MQ	3461	N535MQ	LGA	BNA	NA	764	12	10	2013-09-30 12:00:00
2013	9	30	NA	1159	NA	NA	1344	NA	MQ	3572	N511MQ	LGA	CLE	NA	419	11	59	2013-09-30 11:00:00
2013	9	30	NA	840	NA	NA	1020	NA	MQ	3531	N839MQ	LGA	RDU	NA	431	8	40	2013-09-30 08:00:00

# # Find all unique origin and destination pairs
flights |> 
  distinct(origin, dest)

A tibble: 224 x 2
origin	dest
<chr>	<chr>
EWR	IAH
LGA	IAH
JFK	MIA
JFK	BQN
LGA	ATL
EWR	ORD
EWR	FLL
LGA	IAD
JFK	MCO
LGA	ORD
JFK	PBI
JFK	TPA
JFK	LAX
EWR	SFO
LGA	DFW
JFK	BOS
EWR	LAS
LGA	FLL
EWR	PBI
LGA	MSP
LGA	DTW
EWR	MIA
JFK	ATL
JFK	SFO
JFK	RSW
JFK	SJU
EWR	ATL
EWR	PHX
LGA	MIA
EWR	MSP
...	...
JFK	ACK
LGA	BGR
LGA	MSN
LGA	ORF
JFK	IAH
JFK	MCI
LGA	OMA
LGA	DSM
LGA	GSP
JFK	ABQ
LGA	ILM
LGA	SYR
JFK	MVY
LGA	SBN
JFK	STL
LGA	LEX
EWR	SBN
LGA	MHT
LGA	CAE
JFK	JAC
JFK	SDF
LGA	CHO
JFK	MKE
LGA	AVL
JFK	BHM
LGA	TVC
LGA	MYR
EWR	TVC
EWR	ANC
EWR	LGA

# keep other columns when filtering for unique rows
flights |> 
  distinct(origin, dest, .keep_all = TRUE)

A tibble: 224 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
2013	1	1	622	630	-8	1017	1014	3	US	245	N807AW	EWR	PHX	342	2133	6	30	2013-01-01 06:00:00
2013	1	1	623	610	13	920	915	5	AA	1837	N3EMAA	LGA	MIA	153	1096	6	10	2013-01-01 06:00:00
2013	1	1	624	630	-6	909	840	29	EV	4626	N11107	EWR	MSP	190	1008	6	30	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	10	1	1149	1159	-10	1245	1259	-14	B6	1191	N346JB	JFK	ACK	39	199	11	59	2013-10-01 11:00:00
2013	10	1	1338	1105	153	1446	1245	121	EV	5309	N713EV	LGA	BGR	57	378	11	5	2013-10-01 11:00:00
2013	10	1	1345	1350	-5	1457	1526	-29	EV	5181	N612QX	LGA	MSN	115	812	13	50	2013-10-01 13:00:00
2013	10	1	1543	1545	-2	1702	1721	-19	EV	5293	N398CA	LGA	ORF	46	296	15	45	2013-10-01 15:00:00
2013	10	1	1658	1700	-2	2002	1955	7	AA	211	N3FVAA	JFK	IAH	214	1417	17	0	2013-10-01 17:00:00
2013	10	1	1728	1736	-8	1910	2006	-56	9E	3310	N907XJ	JFK	MCI	143	1113	17	36	2013-10-01 17:00:00
2013	10	1	1732	1730	2	1925	1953	-28	EV	5298	N709EV	LGA	OMA	153	1148	17	30	2013-10-01 17:00:00
2013	10	1	1857	1900	-3	2044	2117	-33	9E	3445	N906XJ	LGA	DSM	146	1031	19	0	2013-10-01 19:00:00
2013	10	1	1930	1900	30	2129	2119	10	9E	3854	N8884E	LGA	GSP	86	610	19	0	2013-10-01 19:00:00
2013	10	1	1955	2001	-6	2213	2248	-35	B6	65	N554JB	JFK	ABQ	230	1826	20	1	2013-10-01 20:00:00
2013	10	1	2051	2110	-19	2219	2306	-47	EV	4885	N752EV	LGA	ILM	66	500	21	10	2013-10-01 21:00:00
2013	10	1	2150	2159	-9	2246	2308	-22	9E	3525	N922XJ	LGA	SYR	34	198	21	59	2013-10-01 21:00:00
2013	10	3	1414	1350	24	1514	1453	21	B6	1338	N368JB	JFK	MVY	36	173	13	50	2013-10-03 13:00:00
2013	10	18	1820	1745	35	2030	2011	19	EV	5624	N748EV	LGA	SBN	104	651	17	45	2013-10-18 17:00:00
2013	11	2	1519	1459	20	1654	1702	-8	DL	567	N329NB	JFK	STL	129	892	14	59	2013-11-02 14:00:00
2013	11	24	2026	2035	-9	2227	2249	-22	9E	3669	N8604C	LGA	LEX	90	604	20	35	2013-11-24 20:00:00
2013	12	1	1241	1215	26	1431	1431	0	EV	3264	N16976	EWR	SBN	94	637	12	15	2013-12-01 12:00:00
2013	12	19	1056	1103	-7	1210	1219	-9	EV	5252	N848AS	LGA	MHT	39	195	11	3	2013-12-19 11:00:00
2013	12	19	1914	1915	-1	2130	2144	-14	EV	5567	N848AS	LGA	CAE	97	617	19	15	2013-12-19 19:00:00
2013	12	21	802	800	2	1115	1102	13	DL	2379	N6705Y	JFK	JAC	281	1894	8	0	2013-12-21 08:00:00
2013	12	21	1610	1610	0	1839	1855	-16	9E	2941	N8930E	JFK	SDF	114	662	16	10	2013-12-21 16:00:00
2013	3	1	2046	2045	1	2206	2220	-14	EV	5343	N197PQ	LGA	CHO	48	305	20	45	2013-03-01 20:00:00
2013	3	2	1606	1610	-4	1723	1758	-35	9E	3437	N927XJ	JFK	MKE	109	745	16	10	2013-03-02 16:00:00
2013	4	14	937	945	-8	1130	1159	-29	9E	3632	N8936A	LGA	AVL	93	599	9	45	2013-04-14 09:00:00
2013	5	25	1007	1000	7	1129	1148	-19	EV	5621	N751EV	JFK	BHM	117	865	10	0	2013-05-25 10:00:00
2013	6	14	1756	1800	-4	2004	2005	-1	MQ	3402	N722MQ	LGA	TVC	101	655	18	0	2013-06-14 18:00:00
2013	6	15	1517	1520	-3	1656	1730	-34	EV	5163	N605QX	LGA	MYR	74	563	15	20	2013-06-15 15:00:00
2013	7	5	1355	1400	-5	1550	1620	-30	EV	4137	N11164	EWR	TVC	93	644	14	0	2013-07-05 14:00:00
2013	7	6	1629	1615	14	1954	1953	1	UA	887	N587UA	EWR	ANC	418	3370	16	15	2013-07-06 16:00:00
2013	7	27	NA	106	NA	NA	245	NA	US	1632	NA	EWR	LGA	NA	17	1	6	2013-07-27 01:00:00

If you want to find the number of occurrences instead, you’re better off swapping distinct() for count(), and with the sort = TRUE argument you can arrange them in descending order of number of occurrences.

flights |>
  count(origin, dest, sort = TRUE)

A tibble: 224 x 3
origin	dest	n
<chr>	<chr>	<int>
JFK	LAX	11262
LGA	ATL	10263
LGA	ORD	8857
JFK	SFO	8204
LGA	CLT	6168
EWR	ORD	6100
JFK	BOS	5898
LGA	MIA	5781
JFK	MCO	5464
EWR	BOS	5327
EWR	SFO	5127
LGA	DTW	5040
EWR	CLT	5026
EWR	ATL	5022
EWR	MCO	4941
EWR	LAX	4912
LGA	DFW	4858
JFK	SJU	4752
LGA	DCA	4716
LGA	BOS	4283
JFK	FLL	4254
LGA	FLL	4008
JFK	LAS	3987
EWR	IAH	3973
EWR	FLL	3793
LGA	MSP	3713
LGA	DEN	3704
LGA	MCO	3677
JFK	BUF	3582
LGA	RDU	3581
...	...	...
JFK	EGE	103
LGA	OMA	95
LGA	IND	87
LGA	TVC	77
LGA	SAV	68
EWR	MYR	56
LGA	CHO	52
EWR	PHL	49
JFK	SDF	46
LGA	GRR	46
EWR	BZN	36
EWR	TVC	24
EWR	JAC	23
JFK	PSP	19
LGA	EYW	17
EWR	HDN	15
EWR	MTJ	15
LGA	BWI	15
LGA	CAE	12
LGA	AVL	10
EWR	ANC	8
LGA	SBN	6
EWR	SBN	4
LGA	MYR	3
JFK	JAC	2
EWR	LGA	1
JFK	BHM	1
JFK	MEM	1
JFK	STL	1
LGA	LEX	1

Exercises

3.2.1. Single pipeline:

Had an arrival delay of two or more hours
Flew to Houston (IAH or HOU)
Were operated by United, American, or Delta
Departed in summer (July, August, and September)
Arrived more than two hours late, but didn’t leave late
Were delayed by at least an hour, but made up over 30 minutes in flight

3.2.2. Sort flights to find the flights with longest departure delays. Find the flights that left earliest in the morning.

3.2.3. Sort flights to find the fastest flights. (Hint: Try including a math calculation inside of your function.)

3.2.4. Was there a flight on every day of 2013?

3.2.5. Which flights traveled the farthest distance? Which traveled the least distance?

3.2.6. Does it matter what order you used filter() and arrange() if you’re using both? Why/why not? Think about the results and how much work the functions would have to do.

#3.2.1. Had an arrival delay of two or more hours

#3.2.1. Flew to Houston (IAH or HOU)

#3.2.1. Were operated by United, American, or Delta
#

#3.2.1. Departed in summer (July, August, and September)

#3.2.1. Arrived more than two hours late, but didn’t leave late

#3.2.1. Were delayed by at least an hour, but made up over 30 minutes in flight

#3.2.2. Sort flights to find the flights with longest departure delays. Find the flights that left earliest in the morning.

#3.2.3. Sort flights to find the fastest flights. (Hint: Try including a math calculation inside of your function.)

#3.2.4. Was there a flight on every day of 2013?

#

#3.2.5. Which flights traveled the farthest distance? Which traveled the least distance?

#3.2.6. Does it matter what order you used filter() and arrange() if you’re using both? Why/why not? 
# Think about the results and how much work the functions would have to do.

Columns

There are four important verbs that affect the columns without changing the rows:

mutate() creates new columns that are derived from the existing columns
select() changes which columns are present
rename() changes the names of the columns
relocate() changes the positions of the columns.

`mutate()`

By default, mutate() adds new columns on the right hand side of your dataset, which makes it difficult to see what’s happening here. We can use the .before argument to instead add the variables to the left hand side.

flights |> 
  mutate(
    gain = dep_delay - arr_delay,       # gain, how much time a delayed flight made up in the air
    speed = distance / air_time * 60,   # the speed in miles per hour
    .after = day                         # try: .before = 1
  )

A tibble: 336776 x 21
year	month	day	gain	speed	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	...	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<dbl>	<dbl>	<int>	<int>	<dbl>	<int>	<int>	...	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	-9	370.0441	517	515	2	830	819	...	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	-16	374.2731	533	529	4	850	830	...	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	-31	408.3750	542	540	2	923	850	...	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	17	516.7213	544	545	-1	1004	1022	...	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	19	394.1379	554	600	-6	812	837	...	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	-16	287.6000	554	558	-4	740	728	...	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	-24	404.4304	555	600	-5	913	854	...	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	11	259.2453	557	600	-3	709	723	...	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	5	404.5714	557	600	-3	838	846	...	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	-10	318.6957	558	600	-2	753	745	...	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	0	413.9597	558	600	-2	849	851	...	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	1	381.6456	558	600	-2	853	856	...	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	-9	430.4348	558	600	-2	924	917	...	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	12	426.3158	558	600	-2	923	937	...	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	-32	324.2802	559	600	-1	941	910	...	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	4	255.0000	559	559	0	702	706	...	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	7	396.4985	559	600	-1	854	902	...	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	7	424.7368	600	600	0	851	858	...	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	-12	341.1940	600	600	0	837	825	...	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	7	417.5510	601	600	1	844	850	...	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	0	360.0000	602	610	-8	812	820	...	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	-19	286.8571	602	605	-3	821	805	...	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	8	428.2895	606	610	-4	858	910	...	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	4	356.2500	606	610	-4	837	845	...	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	17	414.6497	607	607	0	858	915	...	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	-24	310.3597	608	600	8	807	735	...	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	-3	423.9344	611	600	11	945	931	...	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	-1	368.2286	613	610	3	925	921	...	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	21	526.8132	615	615	0	1039	1100	...	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	9	373.0000	615	615	0	833	842	...	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...		...	...	...	...	...	...	...	...	...	...
2013	9	30	22	406.6667	2123	2125	-2	2223	2247	...	EV	5489	N712EV	LGA	CHO	45	305	21	25	2013-09-30 21:00:00
2013	9	30	7	440.8333	2127	2129	-2	2314	2323	...	EV	3833	N16546	EWR	CLT	72	529	21	29	2013-09-30 21:00:00
2013	9	30	29	458.0282	2128	2130	-2	2328	2359	...	B6	97	N807JB	JFK	DEN	213	1626	21	30	2013-09-30 21:00:00
2013	9	30	32	389.3333	2129	2059	30	2230	2232	...	EV	5048	N751EV	LGA	RIC	45	292	20	59	2013-09-30 20:00:00
2013	9	30	21	355.0000	2131	2140	-9	2225	2255	...	MQ	3621	N807MQ	JFK	DCA	36	213	21	40	2013-09-30 21:00:00
2013	9	30	30	498.3221	2140	2140	0	10	40	...	AA	185	N335AA	JFK	LAX	298	2475	21	40	2013-09-30 21:00:00
2013	9	30	2	362.5532	2142	2129	13	2250	2239	...	EV	4509	N12957	EWR	PWM	47	284	21	29	2013-09-30 21:00:00
2013	9	30	25	499.3750	2145	2145	0	115	140	...	B6	1103	N633JB	JFK	SJU	192	1598	21	45	2013-09-30 21:00:00
2013	9	30	7	464.4604	2147	2137	10	30	27	...	B6	1371	N627JB	LGA	FLL	139	1076	21	37	2013-09-30 21:00:00
2013	9	30	16	324.3243	2149	2156	-7	2245	2308	...	UA	523	N813UA	EWR	BOS	37	200	21	56	2013-09-30 21:00:00
2013	9	30	7	321.5385	2150	2159	-9	2250	2306	...	EV	3842	N10575	EWR	MHT	39	209	21	59	2013-09-30 21:00:00
2013	9	30	0	361.2000	2159	1845	194	2344	2030	...	9E	3320	N906XJ	JFK	BUF	50	301	18	45	2013-09-30 18:00:00
2013	9	30	-10	371.8033	2203	2205	-2	2339	2331	...	EV	5311	N722EV	LGA	BGR	61	378	22	5	2013-09-30 22:00:00
2013	9	30	20	472.5773	2207	2140	27	2257	2250	...	MQ	3660	N532MQ	LGA	BNA	97	764	21	40	2013-09-30 21:00:00
2013	9	30	15	436.0000	2211	2059	72	2339	2242	...	EV	4672	N12145	EWR	STL	120	872	20	59	2013-09-30 20:00:00
2013	9	30	7	341.2500	2231	2245	-14	2335	2356	...	B6	108	N193JB	JFK	PWM	48	273	22	45	2013-09-30 22:00:00
2013	9	30	38	483.9623	2233	2113	80	112	30	...	UA	471	N578UA	EWR	SFO	318	2565	21	13	2013-09-30 21:00:00
2013	9	30	24	460.4878	2235	2001	154	59	2249	...	B6	1083	N804JB	JFK	MCO	123	944	20	1	2013-09-30 20:00:00
2013	9	30	0	371.1628	2237	2245	-8	2345	2353	...	B6	234	N318JB	JFK	BTV	43	266	22	45	2013-09-30 22:00:00
2013	9	30	12	305.8537	2240	2245	-5	2334	2351	...	B6	1816	N354JB	JFK	SYR	41	209	22	45	2013-09-30 22:00:00
2013	9	30	10	347.3077	2240	2250	-10	2347	7	...	B6	2002	N281JB	JFK	BUF	52	301	22	50	2013-09-30 22:00:00
2013	9	30	11	337.0213	2241	2246	-5	2345	1	...	B6	486	N346JB	JFK	ROC	47	264	22	46	2013-09-30 22:00:00
2013	9	30	11	340.0000	2307	2255	12	2359	2358	...	B6	718	N565JB	JFK	BOS	33	187	22	55	2013-09-30 22:00:00
2013	9	30	15	495.0000	2349	2359	-10	325	350	...	B6	745	N516JB	JFK	PSE	196	1617	23	59	2013-09-30 23:00:00
2013	9	30	NA	NA	NA	1842	NA	NA	2019	...	EV	5274	N740EV	LGA	BNA	NA	764	18	42	2013-09-30 18:00:00
2013	9	30	NA	NA	NA	1455	NA	NA	1634	...	9E	3393	NA	JFK	DCA	NA	213	14	55	2013-09-30 14:00:00
2013	9	30	NA	NA	NA	2200	NA	NA	2312	...	9E	3525	NA	LGA	SYR	NA	198	22	0	2013-09-30 22:00:00
2013	9	30	NA	NA	NA	1210	NA	NA	1330	...	MQ	3461	N535MQ	LGA	BNA	NA	764	12	10	2013-09-30 12:00:00
2013	9	30	NA	NA	NA	1159	NA	NA	1344	...	MQ	3572	N511MQ	LGA	CLE	NA	419	11	59	2013-09-30 11:00:00
2013	9	30	NA	NA	NA	840	NA	NA	1020	...	MQ	3531	N839MQ	LGA	RDU	NA	431	8	40	2013-09-30 08:00:00

flights |> 
  mutate(
    gain = dep_delay - arr_delay,
    hours = air_time / 60,
    gain_per_hour = gain / hours,
    .keep = "used"
  )

A tibble: 336776 x 6
dep_delay	arr_delay	air_time	gain	hours	gain_per_hour
<dbl>	<dbl>	<dbl>	<dbl>	<dbl>	<dbl>
2	11	227	-9	3.7833333	-2.3788546
4	20	227	-16	3.7833333	-4.2290749
2	33	160	-31	2.6666667	-11.6250000
-1	-18	183	17	3.0500000	5.5737705
-6	-25	116	19	1.9333333	9.8275862
-4	12	150	-16	2.5000000	-6.4000000
-5	19	158	-24	2.6333333	-9.1139241
-3	-14	53	11	0.8833333	12.4528302
-3	-8	140	5	2.3333333	2.1428571
-2	8	138	-10	2.3000000	-4.3478261
-2	-2	149	0	2.4833333	0.0000000
-2	-3	158	1	2.6333333	0.3797468
-2	7	345	-9	5.7500000	-1.5652174
-2	-14	361	12	6.0166667	1.9944598
-1	31	257	-32	4.2833333	-7.4708171
0	-4	44	4	0.7333333	5.4545455
-1	-8	337	7	5.6166667	1.2462908
0	-7	152	7	2.5333333	2.7631579
0	12	134	-12	2.2333333	-5.3731343
1	-6	147	7	2.4500000	2.8571429
-8	-8	170	0	2.8333333	0.0000000
-3	16	105	-19	1.7500000	-10.8571429
-4	-12	152	8	2.5333333	3.1578947
-4	-8	128	4	2.1333333	1.8750000
0	-17	157	17	2.6166667	6.4968153
8	32	139	-24	2.3166667	-10.3597122
11	14	366	-3	6.1000000	-0.4918033
3	4	175	-1	2.9166667	-0.3428571
0	-21	182	21	3.0333333	6.9230769
0	-9	120	9	2.0000000	4.5000000
...	...	...	...	...	...
-2	-24	45	22	0.7500000	29.333333
-2	-9	72	7	1.2000000	5.833333
-2	-31	213	29	3.5500000	8.169014
30	-2	45	32	0.7500000	42.666667
-9	-30	36	21	0.6000000	35.000000
0	-30	298	30	4.9666667	6.040268
13	11	47	2	0.7833333	2.553191
0	-25	192	25	3.2000000	7.812500
10	3	139	7	2.3166667	3.021583
-7	-23	37	16	0.6166667	25.945946
-9	-16	39	7	0.6500000	10.769231
194	194	50	0	0.8333333	0.000000
-2	8	61	-10	1.0166667	-9.836066
27	7	97	20	1.6166667	12.371134
72	57	120	15	2.0000000	7.500000
-14	-21	48	7	0.8000000	8.750000
80	42	318	38	5.3000000	7.169811
154	130	123	24	2.0500000	11.707317
-8	-8	43	0	0.7166667	0.000000
-5	-17	41	12	0.6833333	17.560976
-10	-20	52	10	0.8666667	11.538462
-5	-16	47	11	0.7833333	14.042553
12	1	33	11	0.5500000	20.000000
-10	-25	196	15	3.2666667	4.591837
NA	NA	NA	NA	NA	NA
NA	NA	NA	NA	NA	NA
NA	NA	NA	NA	NA	NA
NA	NA	NA	NA	NA	NA
NA	NA	NA	NA	NA	NA
NA	NA	NA	NA	NA	NA

`select()`

There are a number of helper functions you can use within select():

starts_with("abc"): matches names that begin with “abc”.
ends_with("xyz"): matches names that end with “xyz”.
contains("ijk"): matches names that contain “ijk”.
num_range("x", 1:3): matches x1, x2 and x3.

See ?select for more details

flights |> 
  select(year, month, day)

A tibble: 336776 x 3
year	month	day
<int>	<int>	<int>
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
...	...	...
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30

flights |> 
  select(year:day)

A tibble: 336776 x 3
year	month	day
<int>	<int>	<int>
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
2013	1	1
...	...	...
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30
2013	9	30

flights |> 
  select(!year:day)

A tibble: 336776 x 16
dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2123	2125	-2	2223	2247	-24	EV	5489	N712EV	LGA	CHO	45	305	21	25	2013-09-30 21:00:00
2127	2129	-2	2314	2323	-9	EV	3833	N16546	EWR	CLT	72	529	21	29	2013-09-30 21:00:00
2128	2130	-2	2328	2359	-31	B6	97	N807JB	JFK	DEN	213	1626	21	30	2013-09-30 21:00:00
2129	2059	30	2230	2232	-2	EV	5048	N751EV	LGA	RIC	45	292	20	59	2013-09-30 20:00:00
2131	2140	-9	2225	2255	-30	MQ	3621	N807MQ	JFK	DCA	36	213	21	40	2013-09-30 21:00:00
2140	2140	0	10	40	-30	AA	185	N335AA	JFK	LAX	298	2475	21	40	2013-09-30 21:00:00
2142	2129	13	2250	2239	11	EV	4509	N12957	EWR	PWM	47	284	21	29	2013-09-30 21:00:00
2145	2145	0	115	140	-25	B6	1103	N633JB	JFK	SJU	192	1598	21	45	2013-09-30 21:00:00
2147	2137	10	30	27	3	B6	1371	N627JB	LGA	FLL	139	1076	21	37	2013-09-30 21:00:00
2149	2156	-7	2245	2308	-23	UA	523	N813UA	EWR	BOS	37	200	21	56	2013-09-30 21:00:00
2150	2159	-9	2250	2306	-16	EV	3842	N10575	EWR	MHT	39	209	21	59	2013-09-30 21:00:00
2159	1845	194	2344	2030	194	9E	3320	N906XJ	JFK	BUF	50	301	18	45	2013-09-30 18:00:00
2203	2205	-2	2339	2331	8	EV	5311	N722EV	LGA	BGR	61	378	22	5	2013-09-30 22:00:00
2207	2140	27	2257	2250	7	MQ	3660	N532MQ	LGA	BNA	97	764	21	40	2013-09-30 21:00:00
2211	2059	72	2339	2242	57	EV	4672	N12145	EWR	STL	120	872	20	59	2013-09-30 20:00:00
2231	2245	-14	2335	2356	-21	B6	108	N193JB	JFK	PWM	48	273	22	45	2013-09-30 22:00:00
2233	2113	80	112	30	42	UA	471	N578UA	EWR	SFO	318	2565	21	13	2013-09-30 21:00:00
2235	2001	154	59	2249	130	B6	1083	N804JB	JFK	MCO	123	944	20	1	2013-09-30 20:00:00
2237	2245	-8	2345	2353	-8	B6	234	N318JB	JFK	BTV	43	266	22	45	2013-09-30 22:00:00
2240	2245	-5	2334	2351	-17	B6	1816	N354JB	JFK	SYR	41	209	22	45	2013-09-30 22:00:00
2240	2250	-10	2347	7	-20	B6	2002	N281JB	JFK	BUF	52	301	22	50	2013-09-30 22:00:00
2241	2246	-5	2345	1	-16	B6	486	N346JB	JFK	ROC	47	264	22	46	2013-09-30 22:00:00
2307	2255	12	2359	2358	1	B6	718	N565JB	JFK	BOS	33	187	22	55	2013-09-30 22:00:00
2349	2359	-10	325	350	-25	B6	745	N516JB	JFK	PSE	196	1617	23	59	2013-09-30 23:00:00
NA	1842	NA	NA	2019	NA	EV	5274	N740EV	LGA	BNA	NA	764	18	42	2013-09-30 18:00:00
NA	1455	NA	NA	1634	NA	9E	3393	NA	JFK	DCA	NA	213	14	55	2013-09-30 14:00:00
NA	2200	NA	NA	2312	NA	9E	3525	NA	LGA	SYR	NA	198	22	0	2013-09-30 22:00:00
NA	1210	NA	NA	1330	NA	MQ	3461	N535MQ	LGA	BNA	NA	764	12	10	2013-09-30 12:00:00
NA	1159	NA	NA	1344	NA	MQ	3572	N511MQ	LGA	CLE	NA	419	11	59	2013-09-30 11:00:00
NA	840	NA	NA	1020	NA	MQ	3531	N839MQ	LGA	RDU	NA	431	8	40	2013-09-30 08:00:00

#Select all columns that are characters:

flights |> 
  select(!where(is.character))

A tibble: 336776 x 15
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	flight	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<int>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	1545	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	1714	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	1141	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	725	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	461	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	1696	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	507	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	5708	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	79	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	301	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	49	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	71	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	194	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	1124	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	707	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	1806	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	1187	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	371	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	4650	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	343	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	1919	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	4401	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	1895	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	1743	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	1077	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	3768	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	303	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	135	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	709	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	575	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	9	30	2123	2125	-2	2223	2247	-24	5489	45	305	21	25	2013-09-30 21:00:00
2013	9	30	2127	2129	-2	2314	2323	-9	3833	72	529	21	29	2013-09-30 21:00:00
2013	9	30	2128	2130	-2	2328	2359	-31	97	213	1626	21	30	2013-09-30 21:00:00
2013	9	30	2129	2059	30	2230	2232	-2	5048	45	292	20	59	2013-09-30 20:00:00
2013	9	30	2131	2140	-9	2225	2255	-30	3621	36	213	21	40	2013-09-30 21:00:00
2013	9	30	2140	2140	0	10	40	-30	185	298	2475	21	40	2013-09-30 21:00:00
2013	9	30	2142	2129	13	2250	2239	11	4509	47	284	21	29	2013-09-30 21:00:00
2013	9	30	2145	2145	0	115	140	-25	1103	192	1598	21	45	2013-09-30 21:00:00
2013	9	30	2147	2137	10	30	27	3	1371	139	1076	21	37	2013-09-30 21:00:00
2013	9	30	2149	2156	-7	2245	2308	-23	523	37	200	21	56	2013-09-30 21:00:00
2013	9	30	2150	2159	-9	2250	2306	-16	3842	39	209	21	59	2013-09-30 21:00:00
2013	9	30	2159	1845	194	2344	2030	194	3320	50	301	18	45	2013-09-30 18:00:00
2013	9	30	2203	2205	-2	2339	2331	8	5311	61	378	22	5	2013-09-30 22:00:00
2013	9	30	2207	2140	27	2257	2250	7	3660	97	764	21	40	2013-09-30 21:00:00
2013	9	30	2211	2059	72	2339	2242	57	4672	120	872	20	59	2013-09-30 20:00:00
2013	9	30	2231	2245	-14	2335	2356	-21	108	48	273	22	45	2013-09-30 22:00:00
2013	9	30	2233	2113	80	112	30	42	471	318	2565	21	13	2013-09-30 21:00:00
2013	9	30	2235	2001	154	59	2249	130	1083	123	944	20	1	2013-09-30 20:00:00
2013	9	30	2237	2245	-8	2345	2353	-8	234	43	266	22	45	2013-09-30 22:00:00
2013	9	30	2240	2245	-5	2334	2351	-17	1816	41	209	22	45	2013-09-30 22:00:00
2013	9	30	2240	2250	-10	2347	7	-20	2002	52	301	22	50	2013-09-30 22:00:00
2013	9	30	2241	2246	-5	2345	1	-16	486	47	264	22	46	2013-09-30 22:00:00
2013	9	30	2307	2255	12	2359	2358	1	718	33	187	22	55	2013-09-30 22:00:00
2013	9	30	2349	2359	-10	325	350	-25	745	196	1617	23	59	2013-09-30 23:00:00
2013	9	30	NA	1842	NA	NA	2019	NA	5274	NA	764	18	42	2013-09-30 18:00:00
2013	9	30	NA	1455	NA	NA	1634	NA	3393	NA	213	14	55	2013-09-30 14:00:00
2013	9	30	NA	2200	NA	NA	2312	NA	3525	NA	198	22	0	2013-09-30 22:00:00
2013	9	30	NA	1210	NA	NA	1330	NA	3461	NA	764	12	10	2013-09-30 12:00:00
2013	9	30	NA	1159	NA	NA	1344	NA	3572	NA	419	11	59	2013-09-30 11:00:00
2013	9	30	NA	840	NA	NA	1020	NA	3531	NA	431	8	40	2013-09-30 08:00:00

# rename variable while select
flights |> 
  select(tail_num = tailnum)

A tibble: 336776 x 1
tail_num
<chr>
N14228
N24211
N619AA
N804JB
N668DN
N39463
N516JB
N829AS
N593JB
N3ALAA
N793JB
N657JB
N29129
N53441
N3DUAA
N708JB
N76515
N595JB
N542MQ
N644JB
N971DL
N730MQ
N633AA
N3739P
N53442
N9EAMQ
N532UA
N635JB
N794JB
N326NB
...
N712EV
N16546
N807JB
N751EV
N807MQ
N335AA
N12957
N633JB
N627JB
N813UA
N10575
N906XJ
N722EV
N532MQ
N12145
N193JB
N578UA
N804JB
N318JB
N354JB
N281JB
N346JB
N565JB
N516JB
N740EV
NA
NA
N535MQ
N511MQ
N839MQ

`rename()`

If you want to keep all the existing variables and just want to rename a few, you can use rename() instead of select():

also try: janitor::clean_names()

flights |> 
  rename(tail_num = tailnum)

A tibble: 336776 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tail_num	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	9	30	2123	2125	-2	2223	2247	-24	EV	5489	N712EV	LGA	CHO	45	305	21	25	2013-09-30 21:00:00
2013	9	30	2127	2129	-2	2314	2323	-9	EV	3833	N16546	EWR	CLT	72	529	21	29	2013-09-30 21:00:00
2013	9	30	2128	2130	-2	2328	2359	-31	B6	97	N807JB	JFK	DEN	213	1626	21	30	2013-09-30 21:00:00
2013	9	30	2129	2059	30	2230	2232	-2	EV	5048	N751EV	LGA	RIC	45	292	20	59	2013-09-30 20:00:00
2013	9	30	2131	2140	-9	2225	2255	-30	MQ	3621	N807MQ	JFK	DCA	36	213	21	40	2013-09-30 21:00:00
2013	9	30	2140	2140	0	10	40	-30	AA	185	N335AA	JFK	LAX	298	2475	21	40	2013-09-30 21:00:00
2013	9	30	2142	2129	13	2250	2239	11	EV	4509	N12957	EWR	PWM	47	284	21	29	2013-09-30 21:00:00
2013	9	30	2145	2145	0	115	140	-25	B6	1103	N633JB	JFK	SJU	192	1598	21	45	2013-09-30 21:00:00
2013	9	30	2147	2137	10	30	27	3	B6	1371	N627JB	LGA	FLL	139	1076	21	37	2013-09-30 21:00:00
2013	9	30	2149	2156	-7	2245	2308	-23	UA	523	N813UA	EWR	BOS	37	200	21	56	2013-09-30 21:00:00
2013	9	30	2150	2159	-9	2250	2306	-16	EV	3842	N10575	EWR	MHT	39	209	21	59	2013-09-30 21:00:00
2013	9	30	2159	1845	194	2344	2030	194	9E	3320	N906XJ	JFK	BUF	50	301	18	45	2013-09-30 18:00:00
2013	9	30	2203	2205	-2	2339	2331	8	EV	5311	N722EV	LGA	BGR	61	378	22	5	2013-09-30 22:00:00
2013	9	30	2207	2140	27	2257	2250	7	MQ	3660	N532MQ	LGA	BNA	97	764	21	40	2013-09-30 21:00:00
2013	9	30	2211	2059	72	2339	2242	57	EV	4672	N12145	EWR	STL	120	872	20	59	2013-09-30 20:00:00
2013	9	30	2231	2245	-14	2335	2356	-21	B6	108	N193JB	JFK	PWM	48	273	22	45	2013-09-30 22:00:00
2013	9	30	2233	2113	80	112	30	42	UA	471	N578UA	EWR	SFO	318	2565	21	13	2013-09-30 21:00:00
2013	9	30	2235	2001	154	59	2249	130	B6	1083	N804JB	JFK	MCO	123	944	20	1	2013-09-30 20:00:00
2013	9	30	2237	2245	-8	2345	2353	-8	B6	234	N318JB	JFK	BTV	43	266	22	45	2013-09-30 22:00:00
2013	9	30	2240	2245	-5	2334	2351	-17	B6	1816	N354JB	JFK	SYR	41	209	22	45	2013-09-30 22:00:00
2013	9	30	2240	2250	-10	2347	7	-20	B6	2002	N281JB	JFK	BUF	52	301	22	50	2013-09-30 22:00:00
2013	9	30	2241	2246	-5	2345	1	-16	B6	486	N346JB	JFK	ROC	47	264	22	46	2013-09-30 22:00:00
2013	9	30	2307	2255	12	2359	2358	1	B6	718	N565JB	JFK	BOS	33	187	22	55	2013-09-30 22:00:00
2013	9	30	2349	2359	-10	325	350	-25	B6	745	N516JB	JFK	PSE	196	1617	23	59	2013-09-30 23:00:00
2013	9	30	NA	1842	NA	NA	2019	NA	EV	5274	N740EV	LGA	BNA	NA	764	18	42	2013-09-30 18:00:00
2013	9	30	NA	1455	NA	NA	1634	NA	9E	3393	NA	JFK	DCA	NA	213	14	55	2013-09-30 14:00:00
2013	9	30	NA	2200	NA	NA	2312	NA	9E	3525	NA	LGA	SYR	NA	198	22	0	2013-09-30 22:00:00
2013	9	30	NA	1210	NA	NA	1330	NA	MQ	3461	N535MQ	LGA	BNA	NA	764	12	10	2013-09-30 12:00:00
2013	9	30	NA	1159	NA	NA	1344	NA	MQ	3572	N511MQ	LGA	CLE	NA	419	11	59	2013-09-30 11:00:00
2013	9	30	NA	840	NA	NA	1020	NA	MQ	3531	N839MQ	LGA	RDU	NA	431	8	40	2013-09-30 08:00:00

`relocate()`

By default relocate() moves variables to the front:

flights |> 
  relocate(time_hour, air_time)

# flights |> 
#   relocate(year:dep_time, .after = time_hour)
# flights |> 
#   relocate(starts_with("arr"), .before = dep_time)

A tibble: 336776 x 19
time_hour	air_time	year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	distance	hour	minute
<dttm>	<dbl>	<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>
2013-01-01 05:00:00	227	2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	1400	5	15
2013-01-01 05:00:00	227	2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	1416	5	29
2013-01-01 05:00:00	160	2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	1089	5	40
2013-01-01 05:00:00	183	2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	1576	5	45
2013-01-01 06:00:00	116	2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	762	6	0
2013-01-01 05:00:00	150	2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	719	5	58
2013-01-01 06:00:00	158	2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	1065	6	0
2013-01-01 06:00:00	53	2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	229	6	0
2013-01-01 06:00:00	140	2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	944	6	0
2013-01-01 06:00:00	138	2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	733	6	0
2013-01-01 06:00:00	149	2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	1028	6	0
2013-01-01 06:00:00	158	2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	1005	6	0
2013-01-01 06:00:00	345	2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	2475	6	0
2013-01-01 06:00:00	361	2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	2565	6	0
2013-01-01 06:00:00	257	2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	1389	6	0
2013-01-01 05:00:00	44	2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	187	5	59
2013-01-01 06:00:00	337	2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	2227	6	0
2013-01-01 06:00:00	152	2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	1076	6	0
2013-01-01 06:00:00	134	2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	762	6	0
2013-01-01 06:00:00	147	2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	1023	6	0
2013-01-01 06:00:00	170	2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	1020	6	10
2013-01-01 06:00:00	105	2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	502	6	5
2013-01-01 06:00:00	152	2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	1085	6	10
2013-01-01 06:00:00	128	2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	760	6	10
2013-01-01 06:00:00	157	2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	1085	6	7
2013-01-01 06:00:00	139	2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	719	6	0
2013-01-01 06:00:00	366	2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	2586	6	0
2013-01-01 06:00:00	175	2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	1074	6	10
2013-01-01 06:00:00	182	2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	1598	6	15
2013-01-01 06:00:00	120	2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	746	6	15
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013-09-30 21:00:00	45	2013	9	30	2123	2125	-2	2223	2247	-24	EV	5489	N712EV	LGA	CHO	305	21	25
2013-09-30 21:00:00	72	2013	9	30	2127	2129	-2	2314	2323	-9	EV	3833	N16546	EWR	CLT	529	21	29
2013-09-30 21:00:00	213	2013	9	30	2128	2130	-2	2328	2359	-31	B6	97	N807JB	JFK	DEN	1626	21	30
2013-09-30 20:00:00	45	2013	9	30	2129	2059	30	2230	2232	-2	EV	5048	N751EV	LGA	RIC	292	20	59
2013-09-30 21:00:00	36	2013	9	30	2131	2140	-9	2225	2255	-30	MQ	3621	N807MQ	JFK	DCA	213	21	40
2013-09-30 21:00:00	298	2013	9	30	2140	2140	0	10	40	-30	AA	185	N335AA	JFK	LAX	2475	21	40
2013-09-30 21:00:00	47	2013	9	30	2142	2129	13	2250	2239	11	EV	4509	N12957	EWR	PWM	284	21	29
2013-09-30 21:00:00	192	2013	9	30	2145	2145	0	115	140	-25	B6	1103	N633JB	JFK	SJU	1598	21	45
2013-09-30 21:00:00	139	2013	9	30	2147	2137	10	30	27	3	B6	1371	N627JB	LGA	FLL	1076	21	37
2013-09-30 21:00:00	37	2013	9	30	2149	2156	-7	2245	2308	-23	UA	523	N813UA	EWR	BOS	200	21	56
2013-09-30 21:00:00	39	2013	9	30	2150	2159	-9	2250	2306	-16	EV	3842	N10575	EWR	MHT	209	21	59
2013-09-30 18:00:00	50	2013	9	30	2159	1845	194	2344	2030	194	9E	3320	N906XJ	JFK	BUF	301	18	45
2013-09-30 22:00:00	61	2013	9	30	2203	2205	-2	2339	2331	8	EV	5311	N722EV	LGA	BGR	378	22	5
2013-09-30 21:00:00	97	2013	9	30	2207	2140	27	2257	2250	7	MQ	3660	N532MQ	LGA	BNA	764	21	40
2013-09-30 20:00:00	120	2013	9	30	2211	2059	72	2339	2242	57	EV	4672	N12145	EWR	STL	872	20	59
2013-09-30 22:00:00	48	2013	9	30	2231	2245	-14	2335	2356	-21	B6	108	N193JB	JFK	PWM	273	22	45
2013-09-30 21:00:00	318	2013	9	30	2233	2113	80	112	30	42	UA	471	N578UA	EWR	SFO	2565	21	13
2013-09-30 20:00:00	123	2013	9	30	2235	2001	154	59	2249	130	B6	1083	N804JB	JFK	MCO	944	20	1
2013-09-30 22:00:00	43	2013	9	30	2237	2245	-8	2345	2353	-8	B6	234	N318JB	JFK	BTV	266	22	45
2013-09-30 22:00:00	41	2013	9	30	2240	2245	-5	2334	2351	-17	B6	1816	N354JB	JFK	SYR	209	22	45
2013-09-30 22:00:00	52	2013	9	30	2240	2250	-10	2347	7	-20	B6	2002	N281JB	JFK	BUF	301	22	50
2013-09-30 22:00:00	47	2013	9	30	2241	2246	-5	2345	1	-16	B6	486	N346JB	JFK	ROC	264	22	46
2013-09-30 22:00:00	33	2013	9	30	2307	2255	12	2359	2358	1	B6	718	N565JB	JFK	BOS	187	22	55
2013-09-30 23:00:00	196	2013	9	30	2349	2359	-10	325	350	-25	B6	745	N516JB	JFK	PSE	1617	23	59
2013-09-30 18:00:00	NA	2013	9	30	NA	1842	NA	NA	2019	NA	EV	5274	N740EV	LGA	BNA	764	18	42
2013-09-30 14:00:00	NA	2013	9	30	NA	1455	NA	NA	1634	NA	9E	3393	NA	JFK	DCA	213	14	55
2013-09-30 22:00:00	NA	2013	9	30	NA	2200	NA	NA	2312	NA	9E	3525	NA	LGA	SYR	198	22	0
2013-09-30 12:00:00	NA	2013	9	30	NA	1210	NA	NA	1330	NA	MQ	3461	N535MQ	LGA	BNA	764	12	10
2013-09-30 11:00:00	NA	2013	9	30	NA	1159	NA	NA	1344	NA	MQ	3572	N511MQ	LGA	CLE	419	11	59
2013-09-30 08:00:00	NA	2013	9	30	NA	840	NA	NA	1020	NA	MQ	3531	N839MQ	LGA	RDU	431	8	40

3.3. Exercises

3.3.1 Compare dep_time, sched_dep_time, and dep_delay. How would you expect those three numbers to be related?

3.3.2. Brainstorm as many ways as possible to select dep_time, dep_delay, arr_time, and arr_delay from flights.

3.3.3. What happens if you specify the name of the same variable multiple times in a select() call?

3.3.4. What does the any_of() function do? Why might it be helpful in conjunction with this vector?

variables <- c("year", "month", "day", "dep_delay", "arr_delay")

3.3.5. Does the result of running the following code surprise you? How do the select helpers deal with upper and lower case by default? How can you change that default?

flights |> select(contains("TIME"))

A tibble: 336776 x 6
dep_time	sched_dep_time	arr_time	sched_arr_time	air_time	time_hour
<int>	<int>	<int>	<int>	<dbl>	<dttm>
517	515	830	819	227	2013-01-01 05:00:00
533	529	850	830	227	2013-01-01 05:00:00
542	540	923	850	160	2013-01-01 05:00:00
544	545	1004	1022	183	2013-01-01 05:00:00
554	600	812	837	116	2013-01-01 06:00:00
554	558	740	728	150	2013-01-01 05:00:00
555	600	913	854	158	2013-01-01 06:00:00
557	600	709	723	53	2013-01-01 06:00:00
557	600	838	846	140	2013-01-01 06:00:00
558	600	753	745	138	2013-01-01 06:00:00
558	600	849	851	149	2013-01-01 06:00:00
558	600	853	856	158	2013-01-01 06:00:00
558	600	924	917	345	2013-01-01 06:00:00
558	600	923	937	361	2013-01-01 06:00:00
559	600	941	910	257	2013-01-01 06:00:00
559	559	702	706	44	2013-01-01 05:00:00
559	600	854	902	337	2013-01-01 06:00:00
600	600	851	858	152	2013-01-01 06:00:00
600	600	837	825	134	2013-01-01 06:00:00
601	600	844	850	147	2013-01-01 06:00:00
602	610	812	820	170	2013-01-01 06:00:00
602	605	821	805	105	2013-01-01 06:00:00
606	610	858	910	152	2013-01-01 06:00:00
606	610	837	845	128	2013-01-01 06:00:00
607	607	858	915	157	2013-01-01 06:00:00
608	600	807	735	139	2013-01-01 06:00:00
611	600	945	931	366	2013-01-01 06:00:00
613	610	925	921	175	2013-01-01 06:00:00
615	615	1039	1100	182	2013-01-01 06:00:00
615	615	833	842	120	2013-01-01 06:00:00
...	...	...	...	...	...
2123	2125	2223	2247	45	2013-09-30 21:00:00
2127	2129	2314	2323	72	2013-09-30 21:00:00
2128	2130	2328	2359	213	2013-09-30 21:00:00
2129	2059	2230	2232	45	2013-09-30 20:00:00
2131	2140	2225	2255	36	2013-09-30 21:00:00
2140	2140	10	40	298	2013-09-30 21:00:00
2142	2129	2250	2239	47	2013-09-30 21:00:00
2145	2145	115	140	192	2013-09-30 21:00:00
2147	2137	30	27	139	2013-09-30 21:00:00
2149	2156	2245	2308	37	2013-09-30 21:00:00
2150	2159	2250	2306	39	2013-09-30 21:00:00
2159	1845	2344	2030	50	2013-09-30 18:00:00
2203	2205	2339	2331	61	2013-09-30 22:00:00
2207	2140	2257	2250	97	2013-09-30 21:00:00
2211	2059	2339	2242	120	2013-09-30 20:00:00
2231	2245	2335	2356	48	2013-09-30 22:00:00
2233	2113	112	30	318	2013-09-30 21:00:00
2235	2001	59	2249	123	2013-09-30 20:00:00
2237	2245	2345	2353	43	2013-09-30 22:00:00
2240	2245	2334	2351	41	2013-09-30 22:00:00
2240	2250	2347	7	52	2013-09-30 22:00:00
2241	2246	2345	1	47	2013-09-30 22:00:00
2307	2255	2359	2358	33	2013-09-30 22:00:00
2349	2359	325	350	196	2013-09-30 23:00:00
NA	1842	NA	2019	NA	2013-09-30 18:00:00
NA	1455	NA	1634	NA	2013-09-30 14:00:00
NA	2200	NA	2312	NA	2013-09-30 22:00:00
NA	1210	NA	1330	NA	2013-09-30 12:00:00
NA	1159	NA	1344	NA	2013-09-30 11:00:00
NA	840	NA	1020	NA	2013-09-30 08:00:00

3.3.6. Rename air_time to air_time_min to indicate units of measurement and move it to the beginning of the data frame.

3.3.7. Why doesn’t the following work, and what does the error mean?

flights |> 
  select(tailnum) |> 
  arrange(arr_delay)

Error in `arrange()`:
i In argument: `..1 = arr_delay`.
Caused by error:
! object 'arr_delay' not found
Traceback:


1. arrange(select(flights, tailnum), arr_delay)

2. arrange.data.frame(select(flights, tailnum), arr_delay)

3. arrange_rows(.data, dots = dots, locale = .locale)

4. mutate(data, `:=`("{name}", !!dot), .keep = "none")

5. mutate.data.frame(data, `:=`("{name}", !!dot), .keep = "none")

6. mutate_cols(.data, dplyr_quosures(...), by)

7. withCallingHandlers(for (i in seq_along(dots)) {
 .     poke_error_context(dots, i, mask = mask)
 .     context_poke("column", old_current_column)
 .     new_columns <- mutate_col(dots[[i]], data, mask, new_columns)
 . }, error = dplyr_error_handler(dots = dots, mask = mask, bullets = mutate_bullets, 
 .     error_call = error_call, error_class = "dplyr:::mutate_error"), 
 .     warning = dplyr_warning_handler(state = warnings_state, mask = mask, 
 .         error_call = error_call))

8. mutate_col(dots[[i]], data, mask, new_columns)

9. mask$eval_all_mutate(quo)

10. eval()

11. .handleSimpleError(function (cnd) 
  . {
  .     local_error_context(dots, i = frame[[i_sym]], mask = mask)
  .     if (inherits(cnd, "dplyr:::internal_error")) {
  .         parent <- error_cnd(message = bullets(cnd))
  .     }
  .     else {
  .         parent <- cnd
  .     }
  .     message <- c(cnd_bullet_header(action), i = if (has_active_group_context(mask)) cnd_bullet_cur_group_label())
  .     abort(message, class = error_class, parent = parent, call = error_call)
  . }, "object 'arr_delay' not found", base::quote(NULL))

12. h(simpleError(msg, call))

13. abort(message, class = error_class, parent = parent, call = error_call)

14. signal_abort(cnd, .file)

The pipe

flights |> 
  filter(dest == "IAH") |> 
  mutate(speed = distance / air_time * 60) |> 
  select(year:day, dep_time, carrier, flight, speed) |> 
  arrange(desc(speed))

A tibble: 7198 x 7
year	month	day	dep_time	carrier	flight	speed
<int>	<int>	<int>	<int>	<chr>	<int>	<dbl>
2013	7	9	707	UA	226	521.7391
2013	8	27	1850	UA	1128	521.2270
2013	8	28	902	UA	1711	518.5185
2013	8	28	2122	UA	1022	518.5185
2013	6	11	1628	UA	1178	515.3374
2013	8	27	1017	UA	333	515.3374
2013	8	27	1205	UA	1421	515.3374
2013	8	27	1758	UA	302	515.3374
2013	9	27	521	UA	252	515.3374
2013	8	28	625	UA	559	514.9091
2013	8	28	1505	UA	1695	512.1951
2013	9	7	2025	UA	1022	512.1951
2013	9	8	1830	UA	404	512.1951
2013	8	27	1651	UA	525	511.8072
2013	9	4	542	UA	1714	511.8072
2013	9	6	2006	UA	1128	511.8072
2013	9	8	1849	UA	1128	511.8072
2013	6	11	2017	UA	350	509.0909
2013	7	8	2131	UA	260	509.0909
2013	7	8	2213	UA	1740	509.0909
2013	7	12	1718	UA	268	509.0909
2013	7	19	634	UA	226	509.0909
2013	9	27	2003	UA	1712	509.0909
2013	8	27	1854	UA	315	508.7425
2013	6	11	1517	UA	1611	506.0241
2013	6	15	852	UA	215	506.0241
2013	7	7	1649	UA	1254	506.0241
2013	7	9	851	UA	1711	506.0241
2013	7	9	2001	UA	299	506.0241
2013	7	9	2331	UA	1178	506.0241
...	...	...	...	...	...	...
2013	6	10	NA	UA	318	NA
2013	6	15	2037	UA	1611	NA
2013	6	17	NA	UA	318	NA
2013	6	17	NA	UA	1178	NA
2013	6	19	NA	UA	430	NA
2013	6	19	NA	UA	531	NA
2013	6	20	1256	UA	636	NA
2013	6	22	NA	UA	251	NA
2013	6	25	NA	UA	453	NA
2013	6	27	1951	UA	1611	NA
2013	6	28	NA	UA	768	NA
2013	7	10	1905	AA	1901	NA
2013	7	10	NA	UA	1661	NA
2013	7	11	NA	UA	508	NA
2013	7	16	1302	UA	824	NA
2013	7	17	NA	UA	226	NA
2013	7	22	NA	UA	1259	NA
2013	7	22	NA	UA	1661	NA
2013	7	23	NA	UA	1454	NA
2013	7	28	NA	UA	408	NA
2013	8	2	NA	UA	349	NA
2013	8	13	NA	UA	220	NA
2013	8	14	1537	UA	1178	NA
2013	8	16	1456	UA	1257	NA
2013	9	2	NA	UA	1128	NA
2013	9	12	1815	UA	1695	NA
2013	9	12	NA	UA	404	NA
2013	9	12	NA	UA	525	NA
2013	9	12	NA	UA	1128	NA
2013	9	20	752	UA	1591	NA

What would happen if we didn’t have the pipe? We could nest each function call inside the previous call:

arrange(
  select(
    mutate(
      filter(
        flights, 
        dest == "IAH"
      ),
      speed = distance / air_time * 60
    ),
    year:day, dep_time, carrier, flight, speed
  ),
  desc(speed)
)

A tibble: 7198 x 7
year	month	day	dep_time	carrier	flight	speed
<int>	<int>	<int>	<int>	<chr>	<int>	<dbl>
2013	7	9	707	UA	226	521.7391
2013	8	27	1850	UA	1128	521.2270
2013	8	28	902	UA	1711	518.5185
2013	8	28	2122	UA	1022	518.5185
2013	6	11	1628	UA	1178	515.3374
2013	8	27	1017	UA	333	515.3374
2013	8	27	1205	UA	1421	515.3374
2013	8	27	1758	UA	302	515.3374
2013	9	27	521	UA	252	515.3374
2013	8	28	625	UA	559	514.9091
2013	8	28	1505	UA	1695	512.1951
2013	9	7	2025	UA	1022	512.1951
2013	9	8	1830	UA	404	512.1951
2013	8	27	1651	UA	525	511.8072
2013	9	4	542	UA	1714	511.8072
2013	9	6	2006	UA	1128	511.8072
2013	9	8	1849	UA	1128	511.8072
2013	6	11	2017	UA	350	509.0909
2013	7	8	2131	UA	260	509.0909
2013	7	8	2213	UA	1740	509.0909
2013	7	12	1718	UA	268	509.0909
2013	7	19	634	UA	226	509.0909
2013	9	27	2003	UA	1712	509.0909
2013	8	27	1854	UA	315	508.7425
2013	6	11	1517	UA	1611	506.0241
2013	6	15	852	UA	215	506.0241
2013	7	7	1649	UA	1254	506.0241
2013	7	9	851	UA	1711	506.0241
2013	7	9	2001	UA	299	506.0241
2013	7	9	2331	UA	1178	506.0241
...	...	...	...	...	...	...
2013	6	10	NA	UA	318	NA
2013	6	15	2037	UA	1611	NA
2013	6	17	NA	UA	318	NA
2013	6	17	NA	UA	1178	NA
2013	6	19	NA	UA	430	NA
2013	6	19	NA	UA	531	NA
2013	6	20	1256	UA	636	NA
2013	6	22	NA	UA	251	NA
2013	6	25	NA	UA	453	NA
2013	6	27	1951	UA	1611	NA
2013	6	28	NA	UA	768	NA
2013	7	10	1905	AA	1901	NA
2013	7	10	NA	UA	1661	NA
2013	7	11	NA	UA	508	NA
2013	7	16	1302	UA	824	NA
2013	7	17	NA	UA	226	NA
2013	7	22	NA	UA	1259	NA
2013	7	22	NA	UA	1661	NA
2013	7	23	NA	UA	1454	NA
2013	7	28	NA	UA	408	NA
2013	8	2	NA	UA	349	NA
2013	8	13	NA	UA	220	NA
2013	8	14	1537	UA	1178	NA
2013	8	16	1456	UA	1257	NA
2013	9	2	NA	UA	1128	NA
2013	9	12	1815	UA	1695	NA
2013	9	12	NA	UA	404	NA
2013	9	12	NA	UA	525	NA
2013	9	12	NA	UA	1128	NA
2013	9	20	752	UA	1591	NA

Or we could use a bunch of intermediate objects:

flights1 <- filter(flights, dest == "IAH")
flights2 <- mutate(flights1, speed = distance / air_time * 60)
flights3 <- select(flights2, year:day, dep_time, carrier, flight, speed)
arrange(flights3, desc(speed))

A tibble: 7198 x 7
year	month	day	dep_time	carrier	flight	speed
<int>	<int>	<int>	<int>	<chr>	<int>	<dbl>
2013	7	9	707	UA	226	521.7391
2013	8	27	1850	UA	1128	521.2270
2013	8	28	902	UA	1711	518.5185
2013	8	28	2122	UA	1022	518.5185
2013	6	11	1628	UA	1178	515.3374
2013	8	27	1017	UA	333	515.3374
2013	8	27	1205	UA	1421	515.3374
2013	8	27	1758	UA	302	515.3374
2013	9	27	521	UA	252	515.3374
2013	8	28	625	UA	559	514.9091
2013	8	28	1505	UA	1695	512.1951
2013	9	7	2025	UA	1022	512.1951
2013	9	8	1830	UA	404	512.1951
2013	8	27	1651	UA	525	511.8072
2013	9	4	542	UA	1714	511.8072
2013	9	6	2006	UA	1128	511.8072
2013	9	8	1849	UA	1128	511.8072
2013	6	11	2017	UA	350	509.0909
2013	7	8	2131	UA	260	509.0909
2013	7	8	2213	UA	1740	509.0909
2013	7	12	1718	UA	268	509.0909
2013	7	19	634	UA	226	509.0909
2013	9	27	2003	UA	1712	509.0909
2013	8	27	1854	UA	315	508.7425
2013	6	11	1517	UA	1611	506.0241
2013	6	15	852	UA	215	506.0241
2013	7	7	1649	UA	1254	506.0241
2013	7	9	851	UA	1711	506.0241
2013	7	9	2001	UA	299	506.0241
2013	7	9	2331	UA	1178	506.0241
...	...	...	...	...	...	...
2013	6	10	NA	UA	318	NA
2013	6	15	2037	UA	1611	NA
2013	6	17	NA	UA	318	NA
2013	6	17	NA	UA	1178	NA
2013	6	19	NA	UA	430	NA
2013	6	19	NA	UA	531	NA
2013	6	20	1256	UA	636	NA
2013	6	22	NA	UA	251	NA
2013	6	25	NA	UA	453	NA
2013	6	27	1951	UA	1611	NA
2013	6	28	NA	UA	768	NA
2013	7	10	1905	AA	1901	NA
2013	7	10	NA	UA	1661	NA
2013	7	11	NA	UA	508	NA
2013	7	16	1302	UA	824	NA
2013	7	17	NA	UA	226	NA
2013	7	22	NA	UA	1259	NA
2013	7	22	NA	UA	1661	NA
2013	7	23	NA	UA	1454	NA
2013	7	28	NA	UA	408	NA
2013	8	2	NA	UA	349	NA
2013	8	13	NA	UA	220	NA
2013	8	14	1537	UA	1178	NA
2013	8	16	1456	UA	1257	NA
2013	9	2	NA	UA	1128	NA
2013	9	12	1815	UA	1695	NA
2013	9	12	NA	UA	404	NA
2013	9	12	NA	UA	525	NA
2013	9	12	NA	UA	1128	NA
2013	9	20	752	UA	1591	NA

Groups

`group_by()`

divide your dataset into groups meaningful for your analysis:

flights |> 
  group_by(month)

A grouped_df: 336776 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	9	30	2123	2125	-2	2223	2247	-24	EV	5489	N712EV	LGA	CHO	45	305	21	25	2013-09-30 21:00:00
2013	9	30	2127	2129	-2	2314	2323	-9	EV	3833	N16546	EWR	CLT	72	529	21	29	2013-09-30 21:00:00
2013	9	30	2128	2130	-2	2328	2359	-31	B6	97	N807JB	JFK	DEN	213	1626	21	30	2013-09-30 21:00:00
2013	9	30	2129	2059	30	2230	2232	-2	EV	5048	N751EV	LGA	RIC	45	292	20	59	2013-09-30 20:00:00
2013	9	30	2131	2140	-9	2225	2255	-30	MQ	3621	N807MQ	JFK	DCA	36	213	21	40	2013-09-30 21:00:00
2013	9	30	2140	2140	0	10	40	-30	AA	185	N335AA	JFK	LAX	298	2475	21	40	2013-09-30 21:00:00
2013	9	30	2142	2129	13	2250	2239	11	EV	4509	N12957	EWR	PWM	47	284	21	29	2013-09-30 21:00:00
2013	9	30	2145	2145	0	115	140	-25	B6	1103	N633JB	JFK	SJU	192	1598	21	45	2013-09-30 21:00:00
2013	9	30	2147	2137	10	30	27	3	B6	1371	N627JB	LGA	FLL	139	1076	21	37	2013-09-30 21:00:00
2013	9	30	2149	2156	-7	2245	2308	-23	UA	523	N813UA	EWR	BOS	37	200	21	56	2013-09-30 21:00:00
2013	9	30	2150	2159	-9	2250	2306	-16	EV	3842	N10575	EWR	MHT	39	209	21	59	2013-09-30 21:00:00
2013	9	30	2159	1845	194	2344	2030	194	9E	3320	N906XJ	JFK	BUF	50	301	18	45	2013-09-30 18:00:00
2013	9	30	2203	2205	-2	2339	2331	8	EV	5311	N722EV	LGA	BGR	61	378	22	5	2013-09-30 22:00:00
2013	9	30	2207	2140	27	2257	2250	7	MQ	3660	N532MQ	LGA	BNA	97	764	21	40	2013-09-30 21:00:00
2013	9	30	2211	2059	72	2339	2242	57	EV	4672	N12145	EWR	STL	120	872	20	59	2013-09-30 20:00:00
2013	9	30	2231	2245	-14	2335	2356	-21	B6	108	N193JB	JFK	PWM	48	273	22	45	2013-09-30 22:00:00
2013	9	30	2233	2113	80	112	30	42	UA	471	N578UA	EWR	SFO	318	2565	21	13	2013-09-30 21:00:00
2013	9	30	2235	2001	154	59	2249	130	B6	1083	N804JB	JFK	MCO	123	944	20	1	2013-09-30 20:00:00
2013	9	30	2237	2245	-8	2345	2353	-8	B6	234	N318JB	JFK	BTV	43	266	22	45	2013-09-30 22:00:00
2013	9	30	2240	2245	-5	2334	2351	-17	B6	1816	N354JB	JFK	SYR	41	209	22	45	2013-09-30 22:00:00
2013	9	30	2240	2250	-10	2347	7	-20	B6	2002	N281JB	JFK	BUF	52	301	22	50	2013-09-30 22:00:00
2013	9	30	2241	2246	-5	2345	1	-16	B6	486	N346JB	JFK	ROC	47	264	22	46	2013-09-30 22:00:00
2013	9	30	2307	2255	12	2359	2358	1	B6	718	N565JB	JFK	BOS	33	187	22	55	2013-09-30 22:00:00
2013	9	30	2349	2359	-10	325	350	-25	B6	745	N516JB	JFK	PSE	196	1617	23	59	2013-09-30 23:00:00
2013	9	30	NA	1842	NA	NA	2019	NA	EV	5274	N740EV	LGA	BNA	NA	764	18	42	2013-09-30 18:00:00
2013	9	30	NA	1455	NA	NA	1634	NA	9E	3393	NA	JFK	DCA	NA	213	14	55	2013-09-30 14:00:00
2013	9	30	NA	2200	NA	NA	2312	NA	9E	3525	NA	LGA	SYR	NA	198	22	0	2013-09-30 22:00:00
2013	9	30	NA	1210	NA	NA	1330	NA	MQ	3461	N535MQ	LGA	BNA	NA	764	12	10	2013-09-30 12:00:00
2013	9	30	NA	1159	NA	NA	1344	NA	MQ	3572	N511MQ	LGA	CLE	NA	419	11	59	2013-09-30 11:00:00
2013	9	30	NA	840	NA	NA	1020	NA	MQ	3531	N839MQ	LGA	RDU	NA	431	8	40	2013-09-30 08:00:00

`summarize()`

The most important grouped operation is a summary, which, if being used to calculate a single summary statistic, reduces the data frame to have a single row for each group.

flights |> 
  group_by(month) |> 
  summarize(
    avg_delay = mean(dep_delay)
  )

A tibble: 12 x 2
month	avg_delay
<int>	<dbl>
1	NA
2	NA
3	NA
4	NA
5	NA
6	NA
7	NA
8	NA
9	NA
10	NA
11	NA
12	NA

flights |> 
  group_by(month) |> 
  summarize(
    avg_delay = mean(dep_delay, na.rm = TRUE)
  )

A tibble: 12 x 2
month	avg_delay
<int>	<dbl>
1	10.036665
2	10.816843
3	13.227076
4	13.938038
5	12.986859
6	20.846332
7	21.727787
8	12.611040
9	6.722476
10	6.243988
11	5.435362
12	16.576688

flights |> 
  group_by(month) |> 
  summarize(
    avg_delay = mean(dep_delay, na.rm = TRUE), 
    n = n()
  )

A tibble: 12 x 3
month	avg_delay	n
<int>	<dbl>	<int>
1	10.036665	27004
2	10.816843	24951
3	13.227076	28834
4	13.938038	28330
5	12.986859	28796
6	20.846332	28243
7	21.727787	29425
8	12.611040	29327
9	6.722476	27574
10	6.243988	28889
11	5.435362	27268
12	16.576688	28135

The `slice_` functions

df |> slice_head(n = 1) takes the first row from each group.
df |> slice_tail(n = 1) takes the last row in each group.
df |> slice_min(x, n = 1) takes the row with the smallest value of column x.
df |> slice_max(x, n = 1) takes the row with the largest value of column x.
df |> slice_sample(n = 1) takes one random row.

You can vary n to select more than one row, or instead of n =, you can use prop = 0.1 to select (e.g.) 10% of the rows in each group

flights |> 
  group_by(dest) |> 
  slice_max(arr_delay, with_ties = FALSE, n = 1) |>
  relocate(dest)

A grouped_df: 105 x 19
dest	year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	air_time	distance	hour	minute	time_hour
<chr>	<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
ABQ	2013	7	22	2145	2007	98	132	2259	153	B6	1505	N784JB	JFK	259	1826	20	7	2013-07-22 20:00:00
ACK	2013	7	23	1139	800	219	1250	909	221	B6	1491	N192JB	JFK	44	199	8	0	2013-07-23 08:00:00
ALB	2013	1	25	123	2000	323	229	2101	328	EV	4309	N13908	EWR	30	143	20	0	2013-01-25 20:00:00
ANC	2013	8	17	1740	1625	75	2042	2003	39	UA	887	N528UA	EWR	404	3370	16	25	2013-08-17 16:00:00
ATL	2013	7	22	2257	759	898	121	1026	895	DL	2047	N6716C	LGA	109	762	7	59	2013-07-22 07:00:00
AUS	2013	7	10	2056	1505	351	2347	1758	349	UA	503	N803UA	EWR	192	1504	15	5	2013-07-10 15:00:00
AVL	2013	8	13	1156	832	204	1417	1029	228	EV	4175	N13538	EWR	108	583	8	32	2013-08-13 08:00:00
BDL	2013	2	21	1728	1316	252	1839	1413	266	EV	4103	N16976	EWR	26	116	13	16	2013-02-21 13:00:00
BGR	2013	12	1	1504	1056	248	1628	1230	238	EV	5309	N615QX	LGA	57	378	10	56	2013-12-01 10:00:00
BHM	2013	4	10	25	1900	325	136	2045	291	EV	5038	N713EV	LGA	115	866	19	0	2013-04-10 19:00:00
BNA	2013	1	25	2020	1527	293	2304	1700	364	EV	3835	N14920	EWR	124	748	15	27	2013-01-25 15:00:00
BOS	2013	3	8	1819	1200	379	2005	1303	422	B6	1174	N329JB	EWR	47	200	12	0	2013-03-08 12:00:00
BQN	2013	6	13	6	2034	212	358	30	208	UA	1071	N77296	EWR	216	1585	20	34	2013-06-13 20:00:00
BTV	2013	9	12	2125	1459	386	2258	1622	396	B6	1734	N178JB	JFK	52	266	14	59	2013-09-12 14:00:00
BUF	2013	11	27	1503	815	408	1628	952	396	9E	2906	N930XJ	JFK	56	301	8	15	2013-11-27 08:00:00
BUR	2013	6	27	2146	1800	226	109	2102	247	B6	359	N635JB	JFK	321	2465	18	0	2013-06-27 18:00:00
BWI	2013	1	1	848	1835	853	1001	1950	851	MQ	3944	N942MQ	JFK	41	184	18	35	2013-01-01 18:00:00
BZN	2013	12	28	1104	819	165	1353	1119	154	UA	568	N436UA	EWR	267	1882	8	19	2013-12-28 08:00:00
CAE	2013	4	14	2148	1846	182	2400	2016	224	EV	4471	N15983	EWR	100	602	18	46	2013-04-14 18:00:00
CAK	2013	12	18	1702	950	432	1836	1123	433	FL	160	N972AT	LGA	70	397	9	50	2013-12-18 09:00:00
CHO	2013	3	8	2355	1940	255	109	2121	228	EV	5325	N611QX	LGA	42	305	19	40	2013-03-08 19:00:00
CHS	2013	3	8	1202	751	251	1530	959	331	EV	4532	N15555	EWR	88	628	7	51	2013-03-08 07:00:00
CLE	2013	12	22	2236	1430	486	15	1626	469	EV	4159	N15912	LGA	71	419	14	30	2013-12-22 14:00:00
CLT	2013	2	16	757	1930	747	1013	2149	744	9E	3798	N8940E	JFK	85	541	19	30	2013-02-16 19:00:00
CMH	2013	6	15	1432	1935	1137	1607	2120	1127	MQ	3535	N504MQ	JFK	74	483	19	35	2013-06-15 19:00:00
CRW	2013	4	18	2158	1845	193	2339	2030	189	MQ	4517	N713MQ	LGA	73	444	18	45	2013-04-18 18:00:00
CVG	2013	7	22	845	1600	1005	1044	1815	989	MQ	3075	N665MQ	JFK	96	589	16	0	2013-07-22 16:00:00
DAY	2013	12	5	1504	955	309	1709	1217	292	9E	4060	N8877A	LGA	96	549	9	55	2013-12-05 09:00:00
DCA	2013	2	27	1529	845	404	1639	1015	384	9E	3405	N922XJ	JFK	49	213	8	45	2013-02-27 08:00:00
DEN	2013	2	10	2243	830	853	100	1106	834	F9	835	N203FR	LGA	233	1620	8	30	2013-02-10 08:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
PIT	2013	6	25	1421	805	376	1602	950	372	9E	3611	N8458A	JFK	64	340	8	5	2013-06-25 08:00:00
PSE	2013	6	28	317	2359	198	652	350	182	B6	745	N568JB	JFK	199	1617	23	59	2013-06-28 23:00:00
PSP	2013	3	16	1046	1055	-9	1412	1355	17	VX	55	N839VA	JFK	365	2378	10	55	2013-03-16 10:00:00
PVD	2013	3	18	200	2115	285	259	2214	285	EV	4404	N11547	EWR	27	160	21	15	2013-03-18 21:00:00
PWM	2013	3	8	1300	829	271	1505	955	310	EV	4224	N12540	EWR	52	284	8	29	2013-03-08 08:00:00
RDU	2013	6	13	1833	1250	343	2135	1425	430	MQ	3361	N804MQ	JFK	76	427	12	50	2013-06-13 12:00:00
RIC	2013	7	22	41	1638	483	154	1811	463	EV	4300	N13970	EWR	47	277	16	38	2013-07-22 16:00:00
ROC	2013	6	27	2334	1635	419	32	1805	387	EV	4322	N11191	EWR	40	246	16	35	2013-06-27 16:00:00
RSW	2013	2	27	2138	1658	280	39	2007	272	B6	139	N228JB	JFK	162	1074	16	58	2013-02-27 16:00:00
SAN	2013	6	27	615	1705	790	853	2004	769	DL	503	N372DA	JFK	312	2446	17	5	2013-06-27 17:00:00
SAT	2013	12	1	657	1930	687	1010	2249	681	DL	1091	N342NW	JFK	211	1587	19	30	2013-12-01 19:00:00
SAV	2013	12	5	1735	1024	431	2009	1246	443	EV	4495	N14977	EWR	111	708	10	24	2013-12-05 10:00:00
SBN	2013	11	22	2013	1905	68	2224	2131	53	EV	5383	N398CA	LGA	110	651	19	5	2013-11-22 19:00:00
SDF	2013	7	10	2111	1615	296	57	1900	357	9E	3926	N800AY	JFK	110	662	16	15	2013-07-10 16:00:00
SEA	2013	6	24	159	1735	504	432	2108	444	DL	1543	N727TW	JFK	307	2422	17	35	2013-06-24 17:00:00
SFO	2013	9	20	1139	1845	1014	1457	2210	1007	AA	177	N338AA	JFK	354	2586	18	45	2013-09-20 18:00:00
SJC	2013	7	10	2227	1855	212	202	2216	226	B6	669	N621JB	JFK	338	2569	18	55	2013-07-10 18:00:00
SJU	2013	7	18	2131	1455	396	116	1905	371	AA	1635	N5FNAA	JFK	198	1598	14	55	2013-07-18 14:00:00
SLC	2013	12	19	734	1725	849	1046	2039	847	DL	1223	N375NC	EWR	290	1969	17	25	2013-12-19 17:00:00
SMF	2013	4	19	2346	1845	301	248	2217	271	B6	171	N706JB	JFK	335	2521	18	45	2013-04-19 18:00:00
SNA	2013	7	23	1034	715	199	1307	958	189	UA	288	N514UA	EWR	307	2434	7	15	2013-07-23 07:00:00
SRQ	2013	6	24	1713	1055	378	2205	1411	474	DL	1903	N345NB	LGA	154	1047	10	55	2013-06-24 10:00:00
STL	2013	6	27	753	1830	803	937	2015	802	AA	2019	N571AA	LGA	134	888	18	30	2013-06-27 18:00:00
STT	2013	2	11	1416	810	366	1845	1315	330	AA	655	N625AA	JFK	180	1623	8	10	2013-02-11 08:00:00
SYR	2013	7	10	2257	1705	352	116	1845	391	B6	1516	N238JB	JFK	42	209	17	5	2013-07-10 17:00:00
TPA	2013	4	10	1100	1900	960	1342	2211	931	DL	2391	N959DL	JFK	139	1005	19	0	2013-04-10 19:00:00
TUL	2013	1	20	2347	1936	251	230	2208	262	EV	4333	N14177	EWR	208	1215	19	36	2013-01-20 19:00:00
TVC	2013	8	10	1120	730	230	1323	943	220	EV	5144	N718EV	LGA	96	655	7	30	2013-08-10 07:00:00
TYS	2013	4	12	51	2000	291	250	2209	281	EV	3826	N15986	EWR	103	631	20	0	2013-04-12 20:00:00
XNA	2013	3	8	1311	822	289	1615	1045	330	EV	4140	N18556	EWR	168	1131	8	22	2013-03-08 08:00:00

Grouping by multiple variables

daily <- flights |>  
  group_by(year, month, day)
daily

A grouped_df: 336776 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	9	30	2123	2125	-2	2223	2247	-24	EV	5489	N712EV	LGA	CHO	45	305	21	25	2013-09-30 21:00:00
2013	9	30	2127	2129	-2	2314	2323	-9	EV	3833	N16546	EWR	CLT	72	529	21	29	2013-09-30 21:00:00
2013	9	30	2128	2130	-2	2328	2359	-31	B6	97	N807JB	JFK	DEN	213	1626	21	30	2013-09-30 21:00:00
2013	9	30	2129	2059	30	2230	2232	-2	EV	5048	N751EV	LGA	RIC	45	292	20	59	2013-09-30 20:00:00
2013	9	30	2131	2140	-9	2225	2255	-30	MQ	3621	N807MQ	JFK	DCA	36	213	21	40	2013-09-30 21:00:00
2013	9	30	2140	2140	0	10	40	-30	AA	185	N335AA	JFK	LAX	298	2475	21	40	2013-09-30 21:00:00
2013	9	30	2142	2129	13	2250	2239	11	EV	4509	N12957	EWR	PWM	47	284	21	29	2013-09-30 21:00:00
2013	9	30	2145	2145	0	115	140	-25	B6	1103	N633JB	JFK	SJU	192	1598	21	45	2013-09-30 21:00:00
2013	9	30	2147	2137	10	30	27	3	B6	1371	N627JB	LGA	FLL	139	1076	21	37	2013-09-30 21:00:00
2013	9	30	2149	2156	-7	2245	2308	-23	UA	523	N813UA	EWR	BOS	37	200	21	56	2013-09-30 21:00:00
2013	9	30	2150	2159	-9	2250	2306	-16	EV	3842	N10575	EWR	MHT	39	209	21	59	2013-09-30 21:00:00
2013	9	30	2159	1845	194	2344	2030	194	9E	3320	N906XJ	JFK	BUF	50	301	18	45	2013-09-30 18:00:00
2013	9	30	2203	2205	-2	2339	2331	8	EV	5311	N722EV	LGA	BGR	61	378	22	5	2013-09-30 22:00:00
2013	9	30	2207	2140	27	2257	2250	7	MQ	3660	N532MQ	LGA	BNA	97	764	21	40	2013-09-30 21:00:00
2013	9	30	2211	2059	72	2339	2242	57	EV	4672	N12145	EWR	STL	120	872	20	59	2013-09-30 20:00:00
2013	9	30	2231	2245	-14	2335	2356	-21	B6	108	N193JB	JFK	PWM	48	273	22	45	2013-09-30 22:00:00
2013	9	30	2233	2113	80	112	30	42	UA	471	N578UA	EWR	SFO	318	2565	21	13	2013-09-30 21:00:00
2013	9	30	2235	2001	154	59	2249	130	B6	1083	N804JB	JFK	MCO	123	944	20	1	2013-09-30 20:00:00
2013	9	30	2237	2245	-8	2345	2353	-8	B6	234	N318JB	JFK	BTV	43	266	22	45	2013-09-30 22:00:00
2013	9	30	2240	2245	-5	2334	2351	-17	B6	1816	N354JB	JFK	SYR	41	209	22	45	2013-09-30 22:00:00
2013	9	30	2240	2250	-10	2347	7	-20	B6	2002	N281JB	JFK	BUF	52	301	22	50	2013-09-30 22:00:00
2013	9	30	2241	2246	-5	2345	1	-16	B6	486	N346JB	JFK	ROC	47	264	22	46	2013-09-30 22:00:00
2013	9	30	2307	2255	12	2359	2358	1	B6	718	N565JB	JFK	BOS	33	187	22	55	2013-09-30 22:00:00
2013	9	30	2349	2359	-10	325	350	-25	B6	745	N516JB	JFK	PSE	196	1617	23	59	2013-09-30 23:00:00
2013	9	30	NA	1842	NA	NA	2019	NA	EV	5274	N740EV	LGA	BNA	NA	764	18	42	2013-09-30 18:00:00
2013	9	30	NA	1455	NA	NA	1634	NA	9E	3393	NA	JFK	DCA	NA	213	14	55	2013-09-30 14:00:00
2013	9	30	NA	2200	NA	NA	2312	NA	9E	3525	NA	LGA	SYR	NA	198	22	0	2013-09-30 22:00:00
2013	9	30	NA	1210	NA	NA	1330	NA	MQ	3461	N535MQ	LGA	BNA	NA	764	12	10	2013-09-30 12:00:00
2013	9	30	NA	1159	NA	NA	1344	NA	MQ	3572	N511MQ	LGA	CLE	NA	419	11	59	2013-09-30 11:00:00
2013	9	30	NA	840	NA	NA	1020	NA	MQ	3531	N839MQ	LGA	RDU	NA	431	8	40	2013-09-30 08:00:00

# daily_flights <- daily |> 
#   summarize(n = n())
#> `summarise()` has grouped output by 'year', 'month'. You can override using
#> the `.groups` argument.
daily_flights <- daily |> 
  summarize(
    n = n(), 
    .groups = "drop_last"
  )

Ungrouping

You might also want to remove grouping from a data frame without using summarize(). You can do this with ungroup()

daily |> 
  ungroup()

A tibble: 336776 x 19
year	month	day	dep_time	sched_dep_time	dep_delay	arr_time	sched_arr_time	arr_delay	carrier	flight	tailnum	origin	dest	air_time	distance	hour	minute	time_hour
<int>	<int>	<int>	<int>	<int>	<dbl>	<int>	<int>	<dbl>	<chr>	<int>	<chr>	<chr>	<chr>	<dbl>	<dbl>	<dbl>	<dbl>	<dttm>
2013	1	1	517	515	2	830	819	11	UA	1545	N14228	EWR	IAH	227	1400	5	15	2013-01-01 05:00:00
2013	1	1	533	529	4	850	830	20	UA	1714	N24211	LGA	IAH	227	1416	5	29	2013-01-01 05:00:00
2013	1	1	542	540	2	923	850	33	AA	1141	N619AA	JFK	MIA	160	1089	5	40	2013-01-01 05:00:00
2013	1	1	544	545	-1	1004	1022	-18	B6	725	N804JB	JFK	BQN	183	1576	5	45	2013-01-01 05:00:00
2013	1	1	554	600	-6	812	837	-25	DL	461	N668DN	LGA	ATL	116	762	6	0	2013-01-01 06:00:00
2013	1	1	554	558	-4	740	728	12	UA	1696	N39463	EWR	ORD	150	719	5	58	2013-01-01 05:00:00
2013	1	1	555	600	-5	913	854	19	B6	507	N516JB	EWR	FLL	158	1065	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	709	723	-14	EV	5708	N829AS	LGA	IAD	53	229	6	0	2013-01-01 06:00:00
2013	1	1	557	600	-3	838	846	-8	B6	79	N593JB	JFK	MCO	140	944	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	753	745	8	AA	301	N3ALAA	LGA	ORD	138	733	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	849	851	-2	B6	49	N793JB	JFK	PBI	149	1028	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	853	856	-3	B6	71	N657JB	JFK	TPA	158	1005	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	924	917	7	UA	194	N29129	JFK	LAX	345	2475	6	0	2013-01-01 06:00:00
2013	1	1	558	600	-2	923	937	-14	UA	1124	N53441	EWR	SFO	361	2565	6	0	2013-01-01 06:00:00
2013	1	1	559	600	-1	941	910	31	AA	707	N3DUAA	LGA	DFW	257	1389	6	0	2013-01-01 06:00:00
2013	1	1	559	559	0	702	706	-4	B6	1806	N708JB	JFK	BOS	44	187	5	59	2013-01-01 05:00:00
2013	1	1	559	600	-1	854	902	-8	UA	1187	N76515	EWR	LAS	337	2227	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	851	858	-7	B6	371	N595JB	LGA	FLL	152	1076	6	0	2013-01-01 06:00:00
2013	1	1	600	600	0	837	825	12	MQ	4650	N542MQ	LGA	ATL	134	762	6	0	2013-01-01 06:00:00
2013	1	1	601	600	1	844	850	-6	B6	343	N644JB	EWR	PBI	147	1023	6	0	2013-01-01 06:00:00
2013	1	1	602	610	-8	812	820	-8	DL	1919	N971DL	LGA	MSP	170	1020	6	10	2013-01-01 06:00:00
2013	1	1	602	605	-3	821	805	16	MQ	4401	N730MQ	LGA	DTW	105	502	6	5	2013-01-01 06:00:00
2013	1	1	606	610	-4	858	910	-12	AA	1895	N633AA	EWR	MIA	152	1085	6	10	2013-01-01 06:00:00
2013	1	1	606	610	-4	837	845	-8	DL	1743	N3739P	JFK	ATL	128	760	6	10	2013-01-01 06:00:00
2013	1	1	607	607	0	858	915	-17	UA	1077	N53442	EWR	MIA	157	1085	6	7	2013-01-01 06:00:00
2013	1	1	608	600	8	807	735	32	MQ	3768	N9EAMQ	EWR	ORD	139	719	6	0	2013-01-01 06:00:00
2013	1	1	611	600	11	945	931	14	UA	303	N532UA	JFK	SFO	366	2586	6	0	2013-01-01 06:00:00
2013	1	1	613	610	3	925	921	4	B6	135	N635JB	JFK	RSW	175	1074	6	10	2013-01-01 06:00:00
2013	1	1	615	615	0	1039	1100	-21	B6	709	N794JB	JFK	SJU	182	1598	6	15	2013-01-01 06:00:00
2013	1	1	615	615	0	833	842	-9	DL	575	N326NB	EWR	ATL	120	746	6	15	2013-01-01 06:00:00
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
2013	9	30	2123	2125	-2	2223	2247	-24	EV	5489	N712EV	LGA	CHO	45	305	21	25	2013-09-30 21:00:00
2013	9	30	2127	2129	-2	2314	2323	-9	EV	3833	N16546	EWR	CLT	72	529	21	29	2013-09-30 21:00:00
2013	9	30	2128	2130	-2	2328	2359	-31	B6	97	N807JB	JFK	DEN	213	1626	21	30	2013-09-30 21:00:00
2013	9	30	2129	2059	30	2230	2232	-2	EV	5048	N751EV	LGA	RIC	45	292	20	59	2013-09-30 20:00:00
2013	9	30	2131	2140	-9	2225	2255	-30	MQ	3621	N807MQ	JFK	DCA	36	213	21	40	2013-09-30 21:00:00
2013	9	30	2140	2140	0	10	40	-30	AA	185	N335AA	JFK	LAX	298	2475	21	40	2013-09-30 21:00:00
2013	9	30	2142	2129	13	2250	2239	11	EV	4509	N12957	EWR	PWM	47	284	21	29	2013-09-30 21:00:00
2013	9	30	2145	2145	0	115	140	-25	B6	1103	N633JB	JFK	SJU	192	1598	21	45	2013-09-30 21:00:00
2013	9	30	2147	2137	10	30	27	3	B6	1371	N627JB	LGA	FLL	139	1076	21	37	2013-09-30 21:00:00
2013	9	30	2149	2156	-7	2245	2308	-23	UA	523	N813UA	EWR	BOS	37	200	21	56	2013-09-30 21:00:00
2013	9	30	2150	2159	-9	2250	2306	-16	EV	3842	N10575	EWR	MHT	39	209	21	59	2013-09-30 21:00:00
2013	9	30	2159	1845	194	2344	2030	194	9E	3320	N906XJ	JFK	BUF	50	301	18	45	2013-09-30 18:00:00
2013	9	30	2203	2205	-2	2339	2331	8	EV	5311	N722EV	LGA	BGR	61	378	22	5	2013-09-30 22:00:00
2013	9	30	2207	2140	27	2257	2250	7	MQ	3660	N532MQ	LGA	BNA	97	764	21	40	2013-09-30 21:00:00
2013	9	30	2211	2059	72	2339	2242	57	EV	4672	N12145	EWR	STL	120	872	20	59	2013-09-30 20:00:00
2013	9	30	2231	2245	-14	2335	2356	-21	B6	108	N193JB	JFK	PWM	48	273	22	45	2013-09-30 22:00:00
2013	9	30	2233	2113	80	112	30	42	UA	471	N578UA	EWR	SFO	318	2565	21	13	2013-09-30 21:00:00
2013	9	30	2235	2001	154	59	2249	130	B6	1083	N804JB	JFK	MCO	123	944	20	1	2013-09-30 20:00:00
2013	9	30	2237	2245	-8	2345	2353	-8	B6	234	N318JB	JFK	BTV	43	266	22	45	2013-09-30 22:00:00
2013	9	30	2240	2245	-5	2334	2351	-17	B6	1816	N354JB	JFK	SYR	41	209	22	45	2013-09-30 22:00:00
2013	9	30	2240	2250	-10	2347	7	-20	B6	2002	N281JB	JFK	BUF	52	301	22	50	2013-09-30 22:00:00
2013	9	30	2241	2246	-5	2345	1	-16	B6	486	N346JB	JFK	ROC	47	264	22	46	2013-09-30 22:00:00
2013	9	30	2307	2255	12	2359	2358	1	B6	718	N565JB	JFK	BOS	33	187	22	55	2013-09-30 22:00:00
2013	9	30	2349	2359	-10	325	350	-25	B6	745	N516JB	JFK	PSE	196	1617	23	59	2013-09-30 23:00:00
2013	9	30	NA	1842	NA	NA	2019	NA	EV	5274	N740EV	LGA	BNA	NA	764	18	42	2013-09-30 18:00:00
2013	9	30	NA	1455	NA	NA	1634	NA	9E	3393	NA	JFK	DCA	NA	213	14	55	2013-09-30 14:00:00
2013	9	30	NA	2200	NA	NA	2312	NA	9E	3525	NA	LGA	SYR	NA	198	22	0	2013-09-30 22:00:00
2013	9	30	NA	1210	NA	NA	1330	NA	MQ	3461	N535MQ	LGA	BNA	NA	764	12	10	2013-09-30 12:00:00
2013	9	30	NA	1159	NA	NA	1344	NA	MQ	3572	N511MQ	LGA	CLE	NA	419	11	59	2013-09-30 11:00:00
2013	9	30	NA	840	NA	NA	1020	NA	MQ	3531	N839MQ	LGA	RDU	NA	431	8	40	2013-09-30 08:00:00

daily |> 
  ungroup() |>
  summarize(
    avg_delay = mean(dep_delay, na.rm = TRUE), 
    flights = n()
  )

A tibble: 1 x 2
avg_delay	flights
<dbl>	<int>
12.63907	336776

`.by`

Instead of using group_by() and ungroup()

flights |> 
  summarize(
    delay = mean(dep_delay, na.rm = TRUE), 
    n = n(),
    .by = c(origin, dest)
  )

A tibble: 224 x 4
origin	dest	delay	n
<chr>	<chr>	<dbl>	<int>
EWR	IAH	11.826551	3973
LGA	IAH	9.058986	2951
JFK	MIA	9.336571	3314
JFK	BQN	6.665546	599
LGA	ATL	11.448621	10263
EWR	ORD	14.644163	6100
EWR	FLL	13.532606	3793
LGA	IAD	16.650421	1803
JFK	MCO	10.601583	5464
LGA	ORD	10.740758	8857
JFK	PBI	14.420290	1739
JFK	TPA	12.012855	2987
JFK	LAX	8.522508	11262
EWR	SFO	14.326394	5127
LGA	DFW	5.806151	4858
JFK	BOS	11.694953	5898
EWR	LAS	11.230075	2010
LGA	FLL	12.876453	4008
EWR	PBI	13.962329	2351
LGA	MSP	9.752957	3713
LGA	DTW	7.770528	5040
EWR	MIA	11.615385	2633
JFK	ATL	10.465974	1930
JFK	SFO	11.952691	8204
JFK	RSW	10.082017	1339
JFK	SJU	10.334039	4752
EWR	ATL	15.501738	5022
EWR	PHX	10.635789	2723
LGA	MIA	7.361747	5781
EWR	MSP	15.313163	2377
...	...	...	...
JFK	ACK	6.4566038	265
LGA	BGR	19.4750000	375
LGA	MSN	27.1179245	218
LGA	ORF	16.5538462	206
JFK	IAH	15.6176471	274
JFK	MCI	23.0859375	276
LGA	OMA	27.3695652	95
LGA	DSM	17.2222222	158
LGA	GSP	8.2346939	104
JFK	ABQ	13.7401575	254
LGA	ILM	19.4166667	110
LGA	SYR	19.1107011	293
JFK	MVY	7.0516432	221
LGA	SBN	31.3333333	6
JFK	STL	20.0000000	1
LGA	LEX	-9.0000000	1
EWR	SBN	5.7500000	4
LGA	MHT	24.0370370	142
LGA	CAE	29.5000000	12
JFK	JAC	5.0000000	2
JFK	SDF	23.9767442	46
LGA	CHO	21.3913043	52
JFK	MKE	19.8604651	183
LGA	AVL	-2.6000000	10
JFK	BHM	7.0000000	1
LGA	TVC	23.4109589	77
LGA	MYR	0.6666667	3
EWR	TVC	17.8695652	24
EWR	ANC	12.8750000	8
EWR	LGA	NaN	1

# group by multiple variables
flights |> 
  summarize(
    delay = mean(dep_delay, na.rm = TRUE), 
    n = n(),
    .by = c(origin, dest)
  )

A tibble: 224 x 4
origin	dest	delay	n
<chr>	<chr>	<dbl>	<int>
EWR	IAH	11.826551	3973
LGA	IAH	9.058986	2951
JFK	MIA	9.336571	3314
JFK	BQN	6.665546	599
LGA	ATL	11.448621	10263
EWR	ORD	14.644163	6100
EWR	FLL	13.532606	3793
LGA	IAD	16.650421	1803
JFK	MCO	10.601583	5464
LGA	ORD	10.740758	8857
JFK	PBI	14.420290	1739
JFK	TPA	12.012855	2987
JFK	LAX	8.522508	11262
EWR	SFO	14.326394	5127
LGA	DFW	5.806151	4858
JFK	BOS	11.694953	5898
EWR	LAS	11.230075	2010
LGA	FLL	12.876453	4008
EWR	PBI	13.962329	2351
LGA	MSP	9.752957	3713
LGA	DTW	7.770528	5040
EWR	MIA	11.615385	2633
JFK	ATL	10.465974	1930
JFK	SFO	11.952691	8204
JFK	RSW	10.082017	1339
JFK	SJU	10.334039	4752
EWR	ATL	15.501738	5022
EWR	PHX	10.635789	2723
LGA	MIA	7.361747	5781
EWR	MSP	15.313163	2377
...	...	...	...
JFK	ACK	6.4566038	265
LGA	BGR	19.4750000	375
LGA	MSN	27.1179245	218
LGA	ORF	16.5538462	206
JFK	IAH	15.6176471	274
JFK	MCI	23.0859375	276
LGA	OMA	27.3695652	95
LGA	DSM	17.2222222	158
LGA	GSP	8.2346939	104
JFK	ABQ	13.7401575	254
LGA	ILM	19.4166667	110
LGA	SYR	19.1107011	293
JFK	MVY	7.0516432	221
LGA	SBN	31.3333333	6
JFK	STL	20.0000000	1
LGA	LEX	-9.0000000	1
EWR	SBN	5.7500000	4
LGA	MHT	24.0370370	142
LGA	CAE	29.5000000	12
JFK	JAC	5.0000000	2
JFK	SDF	23.9767442	46
LGA	CHO	21.3913043	52
JFK	MKE	19.8604651	183
LGA	AVL	-2.6000000	10
JFK	BHM	7.0000000	1
LGA	TVC	23.4109589	77
LGA	MYR	0.6666667	3
EWR	TVC	17.8695652	24
EWR	ANC	12.8750000	8
EWR	LGA	NaN	1

Exercises

3.5.1. Which carrier has the worst average delays? Challenge: can you disentangle the effects of bad airports vs. bad carriers? Why/why not? (Hint: think about flights |> group_by(carrier, dest) |> summarize(n()))

3.5.2. Find the flights that are most delayed upon departure from each destination.

3.5.3. How do delays vary over the course of the day. Illustrate your answer with a plot.

3.5.4. What happens if you supply a negative n to slice_min() and friends?

3.5.5. Explain what count() does in terms of the dplyr verbs you just learned. What does the sort argument to count() do?

3.5.6. Suppose we have the following tiny data frame:

df <- tibble(
  x = 1:5,
  y = c("a", "b", "a", "a", "b"),
  z = c("K", "K", "L", "L", "K")
)

a. Write down what you think the output will look like, then check if you were correct, and describe what group_by() does.

df |>
  group_by(y)

A grouped_df: 5 x 3
x	y	z
<int>	<chr>	<chr>
1	a	K
2	b	K
3	a	L
4	a	L
5	b	K

b. Write down what you think the output will look like, then check if you were correct, and describe what arrange() does. Also comment on how it’s different from the group_by() in part (a)?

df |>
  arrange(y)

A tibble: 5 x 3
x	y	z
<int>	<chr>	<chr>
1	a	K
3	a	L
4	a	L
2	b	K
5	b	K

c. Write down what you think the output will look like, then check if you were correct, and describe what the pipeline does.

df |>
  group_by(y) |>
  summarize(mean_x = mean(x))

A tibble: 2 x 2
y	mean_x
<chr>	<dbl>
a	2.666667
b	3.500000

d. Write down what you think the output will look like, then check if you were correct, and describe what the pipeline does. Then, comment on what the message says.

df |>
  group_by(y, z) |>
  summarize(mean_x = mean(x))

[1m[22m`summarise()` has grouped output by 'y'. You can override using the `.groups`
argument.

A grouped_df: 3 x 3
y	z	mean_x
<chr>	<chr>	<dbl>
a	K	1.0
a	L	3.5
b	K	3.5

e. Write down what you think the output will look like, then check if you were correct, and describe what the pipeline does. How is the output different from the one in part (d).

df |>
  group_by(y, z) |>
  summarize(mean_x = mean(x), .groups = "drop")

A tibble: 3 x 3
y	z	mean_x
<chr>	<chr>	<dbl>
a	K	1.0
a	L	3.5
b	K	3.5

f. Write down what you think the outputs will look like, then check if you were correct, and describe what each pipeline does. How are the outputs of the two pipelines different?

df |>
  group_by(y, z) |>
  summarize(mean_x = mean(x))
df |>
  group_by(y, z) |>
  mutate(mean_x = mean(x))

[1m[22m`summarise()` has grouped output by 'y'. You can override using the `.groups`
argument.

A grouped_df: 3 x 3
y	z	mean_x
<chr>	<chr>	<dbl>
a	K	1.0
a	L	3.5
b	K	3.5

A grouped_df: 5 x 4
x	y	z	mean_x
<int>	<chr>	<chr>	<dbl>
1	a	K	1.0
2	b	K	3.5
3	a	L	3.5
4	a	L	3.5
5	b	K	3.5

Case study: aggregates and sample size

Whenever you do any aggregation, it’s always a good idea to include a count (n()). That way, you can ensure that you’re not drawing conclusions based on very small amounts of data. We’ll demonstrate this with some baseball data from the Lahman package. Specifically, we will compare what proportion of times a player gets a hit (H) vs. the number of times they try to put the ball in play (AB):

batters <- Lahman::Batting |> 
  group_by(playerID) |> 
  summarize(
    performance = sum(H, na.rm = TRUE) / sum(AB, na.rm = TRUE),
    n = sum(AB, na.rm = TRUE)
  )
batters

A tibble: 20469 x 3
playerID	performance	n
<chr>	<dbl>	<int>
aardsda01	0.00000000	4
aaronha01	0.30499838	12364
aaronto01	0.22881356	944
aasedo01	0.00000000	5
abadan01	0.09523810	21
abadfe01	0.11111111	9
abadijo01	0.22448980	49
abbated01	0.25361367	3044
abbeybe01	0.16888889	225
abbeych01	0.28075171	1756
abbotco01	0.33333333	3
abbotda01	0.14285714	7
abbotfr01	0.20857700	513
abbotgl01	NaN	0
abbotje01	0.26342282	596
abbotji01	0.09523810	21
abbotku01	0.25587084	2044
abbotky01	0.09677419	31
abbotod01	0.18571429	70
abbotpa01	0.25000000	20
aberal01	0.14000000	100
abercda01	0.00000000	4
abercre01	0.22279793	386
abernbi01	0.00000000	1
abernbr01	0.24423963	868
abernte01	0.20000000	5
abernte02	0.13812155	181
abernwo01	0.00000000	8
aberscl01	0.25139665	179
ablesha01	0.00000000	26
...	...	...
zimmero01	0.27551020	98
zimmery01	0.27742711	6654
zinkch01	NaN	0
zinkwa01	0.00000000	1
zinnfr01	0.00000000	7
zinngu01	0.26926564	1103
zinnji01	0.28333333	120
zinsebi01	NaN	0
zinteal01	0.16666667	78
zipfebu01	0.22033898	354
ziskri01	0.28713064	5144
zitoba01	0.10174419	344
zitzmbi01	0.26693227	1004
zmiched01	0.05882353	17
zobribe01	0.26632653	5880
zoccope01	0.10810811	37
zoldasa01	0.17482517	286
zoskyed01	0.16000000	50
zuberbi01	0.13537118	229
zuberjo01	0.25000000	136
zuberty01	0.00000000	1
zuletju01	0.24712644	174
zumayjo01	NaN	0
zuninmi01	0.20007479	2674
zupcibo01	0.25031447	795
zupofr01	0.16666667	18
zuvelpa01	0.22199593	491
zuverge01	0.14788732	142
zwilldu01	0.28437500	1280
zychto01	NaN	0

batters |> 
  filter(n > 100) |> 
  ggplot(aes(x = n, y = performance)) +
  geom_point(alpha = 1 / 10) + 
  geom_smooth(se = FALSE)

[1m[22m`geom_smooth()` using method = 'gam' and formula = 'y ~ s(x, bs = "cs")'

png

batters |> 
  arrange(desc(performance))

A tibble: 20469 x 3
playerID	performance	n
<chr>	<dbl>	<int>
abramge01	1	1
alberan01	1	1
banisje01	1	1
bartocl01	1	1
bassdo01	1	1
birasst01	1	2
bruneju01	1	1
burnscb01	1	1
cammaer01	1	1
campsh01	1	1
crockcl01	1	1
davenjo01	1	1
davidda01	1	1
devinha01	1	2
dupremi01	1	1
eddydo01	1	1
egeco01	1	1
eubanue01	1	1
fryjo01	1	1
gallaja01	1	1
garcimi02	1	1
garcira01	1	1
gideobr01	1	1
gleasro01	1	1
gowella01	1	1
grasmlo01	1	1
grayda01	1	1
hancory01	1	1
hesslke01	1	1
holloji01	1	1
...	...	...
yardler01	NaN	0
yarnaed01	NaN	0
yeabsbe01	NaN	0
yettri01	NaN	0
ynoami01	NaN	0
yochira01	NaN	0
youngcl01	NaN	0
youngda01	NaN	0
youngda02	NaN	0
youngki01	NaN	0
youngma03	NaN	0
youngti01	NaN	0
yountla01	NaN	0
zabalan01	NaN	0
zagurmi01	NaN	0
zamorda01	NaN	0
zaratma01	NaN	0
zaskeje01	NaN	0
zavadcl01	NaN	0
zavarcl01	NaN	0
zelleba01	NaN	0
zerpaan01	NaN	0
ziemst01	NaN	0
zimmeje02	NaN	0
zimmejo01	NaN	0
zimmeky01	NaN	0
zinkch01	NaN	0
zinsebi01	NaN	0
zumayjo01	NaN	0
zychto01	NaN	0

Summary

In this chapter, you’ve learned the tools that dplyr provides for working with data frames. The tools are roughly grouped into three categories: those that manipulate the rows (like filter() and arrange()), those that manipulate the columns (like select() and mutate()), and those that manipulate groups (like group_by() and summarize()). In this chapter, we’ve focused on these “whole data frame” tools, but you haven’t yet learned much about what you can do with the individual variable.

Tags: R Data Science Data Transformation

R for Data Science (2e)

Day 3. Data Transformation

Introduction

Prerequisites

nycflights13

`dplyr` basics

Rows

`filter()`

`arrange()`

`distinct()`

Exercises

Columns

`mutate()`

`select()`

`rename()`

`relocate()`

3.3. Exercises

The pipe

Groups

`group_by()`

`summarize()`

The `slice_` functions

Grouping by multiple variables

Ungrouping

`.by`

Exercises

Case study: aggregates and sample size

Summary

Introduction

Prerequisites

nycflights13

dplyr basics

Rows

filter()

arrange()

distinct()

Exercises

Columns

mutate()

select()

rename()

relocate()

3.3. Exercises

The pipe

Groups

group_by()

summarize()

The slice_ functions

Grouping by multiple variables

Ungrouping

.by

Exercises

Case study: aggregates and sample size

Summary

`dplyr` basics

`filter()`

`arrange()`

`distinct()`

`mutate()`

`select()`

`rename()`

`relocate()`

`group_by()`

`summarize()`

The `slice_` functions

`.by`