Import data

flights
## # A tibble: 336,776 × 19
##     year month   day dep_time sched_dep_time dep_delay arr_time sched_arr_time
##    <int> <int> <int>    <int>          <int>     <dbl>    <int>          <int>
##  1  2013     1     1      517            515         2      830            819
##  2  2013     1     1      533            529         4      850            830
##  3  2013     1     1      542            540         2      923            850
##  4  2013     1     1      544            545        -1     1004           1022
##  5  2013     1     1      554            600        -6      812            837
##  6  2013     1     1      554            558        -4      740            728
##  7  2013     1     1      555            600        -5      913            854
##  8  2013     1     1      557            600        -3      709            723
##  9  2013     1     1      557            600        -3      838            846
## 10  2013     1     1      558            600        -2      753            745
## # ℹ 336,766 more rows
## # ℹ 11 more variables: arr_delay <dbl>, carrier <chr>, flight <int>,
## #   tailnum <chr>, origin <chr>, dest <chr>, air_time <dbl>, distance <dbl>,
## #   hour <dbl>, minute <dbl>, time_hour <dttm>

Filter rows

filter(flights, month == 1, day == 1  )
## # A tibble: 842 × 19
##     year month   day dep_time sched_dep_time dep_delay arr_time sched_arr_time
##    <int> <int> <int>    <int>          <int>     <dbl>    <int>          <int>
##  1  2013     1     1      517            515         2      830            819
##  2  2013     1     1      533            529         4      850            830
##  3  2013     1     1      542            540         2      923            850
##  4  2013     1     1      544            545        -1     1004           1022
##  5  2013     1     1      554            600        -6      812            837
##  6  2013     1     1      554            558        -4      740            728
##  7  2013     1     1      555            600        -5      913            854
##  8  2013     1     1      557            600        -3      709            723
##  9  2013     1     1      557            600        -3      838            846
## 10  2013     1     1      558            600        -2      753            745
## # ℹ 832 more rows
## # ℹ 11 more variables: arr_delay <dbl>, carrier <chr>, flight <int>,
## #   tailnum <chr>, origin <chr>, dest <chr>, air_time <dbl>, distance <dbl>,
## #   hour <dbl>, minute <dbl>, time_hour <dttm>
filter(flights, month == 1 & day == 1  )
## # A tibble: 842 × 19
##     year month   day dep_time sched_dep_time dep_delay arr_time sched_arr_time
##    <int> <int> <int>    <int>          <int>     <dbl>    <int>          <int>
##  1  2013     1     1      517            515         2      830            819
##  2  2013     1     1      533            529         4      850            830
##  3  2013     1     1      542            540         2      923            850
##  4  2013     1     1      544            545        -1     1004           1022
##  5  2013     1     1      554            600        -6      812            837
##  6  2013     1     1      554            558        -4      740            728
##  7  2013     1     1      555            600        -5      913            854
##  8  2013     1     1      557            600        -3      709            723
##  9  2013     1     1      557            600        -3      838            846
## 10  2013     1     1      558            600        -2      753            745
## # ℹ 832 more rows
## # ℹ 11 more variables: arr_delay <dbl>, carrier <chr>, flight <int>,
## #   tailnum <chr>, origin <chr>, dest <chr>, air_time <dbl>, distance <dbl>,
## #   hour <dbl>, minute <dbl>, time_hour <dttm>
filter(flights, month == 1 | day == 1  )
## # A tibble: 37,198 × 19
##     year month   day dep_time sched_dep_time dep_delay arr_time sched_arr_time
##    <int> <int> <int>    <int>          <int>     <dbl>    <int>          <int>
##  1  2013     1     1      517            515         2      830            819
##  2  2013     1     1      533            529         4      850            830
##  3  2013     1     1      542            540         2      923            850
##  4  2013     1     1      544            545        -1     1004           1022
##  5  2013     1     1      554            600        -6      812            837
##  6  2013     1     1      554            558        -4      740            728
##  7  2013     1     1      555            600        -5      913            854
##  8  2013     1     1      557            600        -3      709            723
##  9  2013     1     1      557            600        -3      838            846
## 10  2013     1     1      558            600        -2      753            745
## # ℹ 37,188 more rows
## # ℹ 11 more variables: arr_delay <dbl>, carrier <chr>, flight <int>,
## #   tailnum <chr>, origin <chr>, dest <chr>, air_time <dbl>, distance <dbl>,
## #   hour <dbl>, minute <dbl>, time_hour <dttm>
filter(flights, month %in% c(11, 12))
## # A tibble: 55,403 × 19
##     year month   day dep_time sched_dep_time dep_delay arr_time sched_arr_time
##    <int> <int> <int>    <int>          <int>     <dbl>    <int>          <int>
##  1  2013    11     1        5           2359         6      352            345
##  2  2013    11     1       35           2250       105      123           2356
##  3  2013    11     1      455            500        -5      641            651
##  4  2013    11     1      539            545        -6      856            827
##  5  2013    11     1      542            545        -3      831            855
##  6  2013    11     1      549            600       -11      912            923
##  7  2013    11     1      550            600       -10      705            659
##  8  2013    11     1      554            600        -6      659            701
##  9  2013    11     1      554            600        -6      826            827
## 10  2013    11     1      554            600        -6      749            751
## # ℹ 55,393 more rows
## # ℹ 11 more variables: arr_delay <dbl>, carrier <chr>, flight <int>,
## #   tailnum <chr>, origin <chr>, dest <chr>, air_time <dbl>, distance <dbl>,
## #   hour <dbl>, minute <dbl>, time_hour <dttm>

Arrange rows

arrange(flights, desc(month), desc(day))
## # A tibble: 336,776 × 19
##     year month   day dep_time sched_dep_time dep_delay arr_time sched_arr_time
##    <int> <int> <int>    <int>          <int>     <dbl>    <int>          <int>
##  1  2013    12    31       13           2359        14      439            437
##  2  2013    12    31       18           2359        19      449            444
##  3  2013    12    31       26           2245       101      129           2353
##  4  2013    12    31      459            500        -1      655            651
##  5  2013    12    31      514            515        -1      814            812
##  6  2013    12    31      549            551        -2      925            900
##  7  2013    12    31      550            600       -10      725            745
##  8  2013    12    31      552            600        -8      811            826
##  9  2013    12    31      553            600        -7      741            754
## 10  2013    12    31      554            550         4     1024           1027
## # ℹ 336,766 more rows
## # ℹ 11 more variables: arr_delay <dbl>, carrier <chr>, flight <int>,
## #   tailnum <chr>, origin <chr>, dest <chr>, air_time <dbl>, distance <dbl>,
## #   hour <dbl>, minute <dbl>, time_hour <dttm>

Select columns

select(flights,year:dep_time)
## # A tibble: 336,776 × 4
##     year month   day dep_time
##    <int> <int> <int>    <int>
##  1  2013     1     1      517
##  2  2013     1     1      533
##  3  2013     1     1      542
##  4  2013     1     1      544
##  5  2013     1     1      554
##  6  2013     1     1      554
##  7  2013     1     1      555
##  8  2013     1     1      557
##  9  2013     1     1      557
## 10  2013     1     1      558
## # ℹ 336,766 more rows
select(flights, year, month, day,dep_time)
## # A tibble: 336,776 × 4
##     year month   day dep_time
##    <int> <int> <int>    <int>
##  1  2013     1     1      517
##  2  2013     1     1      533
##  3  2013     1     1      542
##  4  2013     1     1      544
##  5  2013     1     1      554
##  6  2013     1     1      554
##  7  2013     1     1      555
##  8  2013     1     1      557
##  9  2013     1     1      557
## 10  2013     1     1      558
## # ℹ 336,766 more rows
select(flights, year, month, day,dep_time, dep_delay)
## # A tibble: 336,776 × 5
##     year month   day dep_time dep_delay
##    <int> <int> <int>    <int>     <dbl>
##  1  2013     1     1      517         2
##  2  2013     1     1      533         4
##  3  2013     1     1      542         2
##  4  2013     1     1      544        -1
##  5  2013     1     1      554        -6
##  6  2013     1     1      554        -4
##  7  2013     1     1      555        -5
##  8  2013     1     1      557        -3
##  9  2013     1     1      557        -3
## 10  2013     1     1      558        -2
## # ℹ 336,766 more rows
select(flights, year, month, day, starts_with("dep"))
## # A tibble: 336,776 × 5
##     year month   day dep_time dep_delay
##    <int> <int> <int>    <int>     <dbl>
##  1  2013     1     1      517         2
##  2  2013     1     1      533         4
##  3  2013     1     1      542         2
##  4  2013     1     1      544        -1
##  5  2013     1     1      554        -6
##  6  2013     1     1      554        -4
##  7  2013     1     1      555        -5
##  8  2013     1     1      557        -3
##  9  2013     1     1      557        -3
## 10  2013     1     1      558        -2
## # ℹ 336,766 more rows
select(flights, year, month, day, contains("time")) 
## # A tibble: 336,776 × 9
##     year month   day dep_time sched_dep_time arr_time sched_arr_time air_time
##    <int> <int> <int>    <int>          <int>    <int>          <int>    <dbl>
##  1  2013     1     1      517            515      830            819      227
##  2  2013     1     1      533            529      850            830      227
##  3  2013     1     1      542            540      923            850      160
##  4  2013     1     1      544            545     1004           1022      183
##  5  2013     1     1      554            600      812            837      116
##  6  2013     1     1      554            558      740            728      150
##  7  2013     1     1      555            600      913            854      158
##  8  2013     1     1      557            600      709            723       53
##  9  2013     1     1      557            600      838            846      140
## 10  2013     1     1      558            600      753            745      138
## # ℹ 336,766 more rows
## # ℹ 1 more variable: time_hour <dttm>
select(flights, year, month, day, ends_with("time")) 
## # A tibble: 336,776 × 8
##     year month   day dep_time sched_dep_time arr_time sched_arr_time air_time
##    <int> <int> <int>    <int>          <int>    <int>          <int>    <dbl>
##  1  2013     1     1      517            515      830            819      227
##  2  2013     1     1      533            529      850            830      227
##  3  2013     1     1      542            540      923            850      160
##  4  2013     1     1      544            545     1004           1022      183
##  5  2013     1     1      554            600      812            837      116
##  6  2013     1     1      554            558      740            728      150
##  7  2013     1     1      555            600      913            854      158
##  8  2013     1     1      557            600      709            723       53
##  9  2013     1     1      557            600      838            846      140
## 10  2013     1     1      558            600      753            745      138
## # ℹ 336,766 more rows
select(flights, year, month, day, contains("time"), everything())
## # A tibble: 336,776 × 19
##     year month   day dep_time sched_dep_time arr_time sched_arr_time air_time
##    <int> <int> <int>    <int>          <int>    <int>          <int>    <dbl>
##  1  2013     1     1      517            515      830            819      227
##  2  2013     1     1      533            529      850            830      227
##  3  2013     1     1      542            540      923            850      160
##  4  2013     1     1      544            545     1004           1022      183
##  5  2013     1     1      554            600      812            837      116
##  6  2013     1     1      554            558      740            728      150
##  7  2013     1     1      555            600      913            854      158
##  8  2013     1     1      557            600      709            723       53
##  9  2013     1     1      557            600      838            846      140
## 10  2013     1     1      558            600      753            745      138
## # ℹ 336,766 more rows
## # ℹ 11 more variables: time_hour <dttm>, dep_delay <dbl>, arr_delay <dbl>,
## #   carrier <chr>, flight <int>, tailnum <chr>, origin <chr>, dest <chr>,
## #   distance <dbl>, hour <dbl>, minute <dbl>

Add columns

library(tidyverse)
library(nycflights13)

mutate(flights,
      gain = dep_delay - arr_delay) %>%

# Select year, month, day, and gain
 select (year:day,gain)
## # A tibble: 336,776 × 4
##     year month   day  gain
##    <int> <int> <int> <dbl>
##  1  2013     1     1    -9
##  2  2013     1     1   -16
##  3  2013     1     1   -31
##  4  2013     1     1    17
##  5  2013     1     1    19
##  6  2013     1     1   -16
##  7  2013     1     1   -24
##  8  2013     1     1    11
##  9  2013     1     1     5
## 10  2013     1     1   -10
## # ℹ 336,766 more rows
# Just keep gain
mutate(flights,
       gain = dep_delay - arr_delay) %>%
# select year, month, day, and gain
    select (gain)
## # A tibble: 336,776 × 1
##     gain
##    <dbl>
##  1    -9
##  2   -16
##  3   -31
##  4    17
##  5    19
##  6   -16
##  7   -24
##  8    11
##  9     5
## 10   -10
## # ℹ 336,766 more rows
# alternative using transmute()
transmute(flights, 
          gain = dep_delay - arr_delay)
## # A tibble: 336,776 × 1
##     gain
##    <dbl>
##  1    -9
##  2   -16
##  3   -31
##  4    17
##  5    19
##  6   -16
##  7   -24
##  8    11
##  9     5
## 10   -10
## # ℹ 336,766 more rows
# lag()
select(flights, dep_time) %>% 
    mutate(dep_time_lag1 = lag(dep_time))
## # A tibble: 336,776 × 2
##    dep_time dep_time_lag1
##       <int>         <int>
##  1      517            NA
##  2      533           517
##  3      542           533
##  4      544           542
##  5      554           544
##  6      554           554
##  7      555           554
##  8      557           555
##  9      557           557
## 10      558           557
## # ℹ 336,766 more rows
# cumsum()
select(flights, minute)%>%
    
    mutate(minute_cumsumn = cumsum(minute))
## # A tibble: 336,776 × 2
##    minute minute_cumsumn
##     <dbl>          <dbl>
##  1     15             15
##  2     29             44
##  3     40             84
##  4     45            129
##  5      0            129
##  6     58            187
##  7      0            187
##  8      0            187
##  9      0            187
## 10      0            187
## # ℹ 336,766 more rows


# Summarize by groups

``` r
library(tidyverse)
library(nycflights13)

# View the flights dataset
glimpse(flights)
## Rows: 336,776
## Columns: 19
## $ year           <int> 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2…
## $ month          <int> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1…
## $ day            <int> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1…
## $ dep_time       <int> 517, 533, 542, 544, 554, 554, 555, 557, 557, 558, 558, …
## $ sched_dep_time <int> 515, 529, 540, 545, 600, 558, 600, 600, 600, 600, 600, …
## $ dep_delay      <dbl> 2, 4, 2, -1, -6, -4, -5, -3, -3, -2, -2, -2, -2, -2, -1…
## $ arr_time       <int> 830, 850, 923, 1004, 812, 740, 913, 709, 838, 753, 849,…
## $ sched_arr_time <int> 819, 830, 850, 1022, 837, 728, 854, 723, 846, 745, 851,…
## $ arr_delay      <dbl> 11, 20, 33, -18, -25, 12, 19, -14, -8, 8, -2, -3, 7, -1…
## $ carrier        <chr> "UA", "UA", "AA", "B6", "DL", "UA", "B6", "EV", "B6", "…
## $ flight         <int> 1545, 1714, 1141, 725, 461, 1696, 507, 5708, 79, 301, 4…
## $ tailnum        <chr> "N14228", "N24211", "N619AA", "N804JB", "N668DN", "N394…
## $ origin         <chr> "EWR", "LGA", "JFK", "JFK", "LGA", "EWR", "EWR", "LGA",…
## $ dest           <chr> "IAH", "IAH", "MIA", "BQN", "ATL", "ORD", "FLL", "IAD",…
## $ air_time       <dbl> 227, 227, 160, 183, 116, 150, 158, 53, 140, 138, 149, 1…
## $ distance       <dbl> 1400, 1416, 1089, 1576, 762, 719, 1065, 229, 944, 733, …
## $ hour           <dbl> 5, 5, 5, 5, 6, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 6, 6, 6…
## $ minute         <dbl> 15, 29, 40, 45, 0, 58, 0, 0, 0, 0, 0, 0, 0, 0, 0, 59, 0…
## $ time_hour      <dttm> 2013-01-01 05:00:00, 2013-01-01 05:00:00, 2013-01-01 0…
# Average departure delay
summarize(flights,
          delay = mean(dep_delay, na.rm = TRUE))
## # A tibble: 1 × 1
##   delay
##   <dbl>
## 1  12.6
# Average departure delay by airline
flights %>%
  group_by(carrier) %>%
  summarize(delay = mean(dep_delay, na.rm = TRUE)) %>%
  arrange(delay)
## # A tibble: 16 × 2
##    carrier delay
##    <chr>   <dbl>
##  1 US       3.78
##  2 HA       4.90
##  3 AS       5.80
##  4 AA       8.59
##  5 DL       9.26
##  6 MQ      10.6 
##  7 UA      12.1 
##  8 OO      12.6 
##  9 VX      12.9 
## 10 B6      13.0 
## 11 9E      16.7 
## 12 WN      17.7 
## 13 FL      18.7 
## 14 YV      19.0 
## 15 EV      20.0 
## 16 F9      20.2
# Count flights by destination
flights %>%
  group_by(dest) %>%
  summarize(count = n())
## # A tibble: 105 × 2
##    dest  count
##    <chr> <int>
##  1 ABQ     254
##  2 ACK     265
##  3 ALB     439
##  4 ANC       8
##  5 ATL   17215
##  6 AUS    2439
##  7 AVL     275
##  8 BDL     443
##  9 BGR     375
## 10 BHM     297
## # ℹ 95 more rows
# Flight count, average distance, and average arrival delay by destination
flights %>%
  group_by(dest) %>%
  summarize(
    count = n(),
    distance = mean(distance, na.rm = TRUE),
    delay = mean(arr_delay, na.rm = TRUE)
  )
## # A tibble: 105 × 4
##    dest  count distance delay
##    <chr> <int>    <dbl> <dbl>
##  1 ABQ     254    1826   4.38
##  2 ACK     265     199   4.85
##  3 ALB     439     143  14.4 
##  4 ANC       8    3370  -2.5 
##  5 ATL   17215     757. 11.3 
##  6 AUS    2439    1514.  6.02
##  7 AVL     275     584.  8.00
##  8 BDL     443     116   7.05
##  9 BGR     375     378   8.03
## 10 BHM     297     866. 16.9 
## # ℹ 95 more rows
# Remove flights with missing departure or arrival delays
not_cancelled <- flights %>%
  filter(!is.na(dep_delay), !is.na(arr_delay))

# Average arrival delay and number of flights by airplane
not_cancelled %>%
  group_by
## # A tibble: 327,346 × 19
##     year month   day dep_time sched_dep_time dep_delay arr_time sched_arr_time
##    <int> <int> <int>    <int>          <int>     <dbl>    <int>          <int>
##  1  2013     1     1      517            515         2      830            819
##  2  2013     1     1      533            529         4      850            830
##  3  2013     1     1      542            540         2      923            850
##  4  2013     1     1      544            545        -1     1004           1022
##  5  2013     1     1      554            600        -6      812            837
##  6  2013     1     1      554            558        -4      740            728
##  7  2013     1     1      555            600        -5      913            854
##  8  2013     1     1      557            600        -3      709            723
##  9  2013     1     1      557            600        -3      838            846
## 10  2013     1     1      558            600        -2      753            745
## # ℹ 327,336 more rows
## # ℹ 11 more variables: arr_delay <dbl>, carrier <chr>, flight <int>,
## #   tailnum <chr>, origin <chr>, dest <chr>, air_time <dbl>, distance <dbl>,
## #   hour <dbl>, minute <dbl>, time_hour <dttm>