library(tidyverse)
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options(repos = c(CRAN = "https://cloud.r-project.org"))


``` r
pacman::p_load(nycflights13)
library(nycflights13)
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…
sortf <- arrange(flights, desc(dep_delay)) 
select(sortf, carrier, flight, tailnum, everything())
## # A tibble: 336,776 × 19
##    carrier flight tailnum  year month   day dep_time sched_dep_time dep_delay
##    <chr>    <int> <chr>   <int> <int> <int>    <int>          <int>     <dbl>
##  1 HA          51 N384HA   2013     1     9      641            900      1301
##  2 MQ        3535 N504MQ   2013     6    15     1432           1935      1137
##  3 MQ        3695 N517MQ   2013     1    10     1121           1635      1126
##  4 AA         177 N338AA   2013     9    20     1139           1845      1014
##  5 MQ        3075 N665MQ   2013     7    22      845           1600      1005
##  6 DL        2391 N959DL   2013     4    10     1100           1900       960
##  7 DL        2119 N927DA   2013     3    17     2321            810       911
##  8 DL        2007 N3762Y   2013     6    27      959           1900       899
##  9 DL        2047 N6716C   2013     7    22     2257            759       898
## 10 AA         172 N5DMAA   2013    12     5      756           1700       896
## # ℹ 336,766 more rows
## # ℹ 10 more variables: arr_time <int>, sched_arr_time <int>, arr_delay <dbl>,
## #   origin <chr>, dest <chr>, air_time <dbl>, distance <dbl>, hour <dbl>,
## #   minute <dbl>, time_hour <dttm>
maxdep <- max(flights$dep_delay, na.rm=TRUE) 
maxdep_id <- which(flights$dep_delay==maxdep) 
flights[maxdep_id, 10:12]
## # A tibble: 1 × 3
##   carrier flight tailnum
##   <chr>    <int> <chr>  
## 1 HA          51 N384HA
summarise(flights, delay=mean(dep_delay,na.rm=TRUE))
## # A tibble: 1 × 1
##   delay
##   <dbl>
## 1  12.6
select(flights, starts_with("dep"))
## # A tibble: 336,776 × 2
##    dep_time dep_delay
##       <int>     <dbl>
##  1      517         2
##  2      533         4
##  3      542         2
##  4      544        -1
##  5      554        -6
##  6      554        -4
##  7      555        -5
##  8      557        -3
##  9      557        -3
## 10      558        -2
## # ℹ 336,766 more rows
not_cancelled <- flights %>% filter(!is.na(dep_delay))
not_cancelled %>%
group_by(year, month, day) %>% summarise(mean=mean(dep_delay))
## `summarise()` has grouped output by 'year', 'month'. You can override using the
## `.groups` argument.
## # A tibble: 365 × 4
## # Groups:   year, month [12]
##     year month   day  mean
##    <int> <int> <int> <dbl>
##  1  2013     1     1 11.5 
##  2  2013     1     2 13.9 
##  3  2013     1     3 11.0 
##  4  2013     1     4  8.95
##  5  2013     1     5  5.73
##  6  2013     1     6  7.15
##  7  2013     1     7  5.42
##  8  2013     1     8  2.55
##  9  2013     1     9  2.28
## 10  2013     1    10  2.84
## # ℹ 355 more rows
not_cancelled <- flights %>% 
filter(!is.na(dep_delay), !is.na(arr_delay))
delays <- not_cancelled %>% group_by(tailnum) %>% summarise(
delay = mean(arr_delay) )
flights %>%
group_by(year, month, day) %>% 
summarise(mean=mean(dep_delay, na.rm =TRUE))
## `summarise()` has grouped output by 'year', 'month'. You can override using the
## `.groups` argument.
## # A tibble: 365 × 4
## # Groups:   year, month [12]
##     year month   day  mean
##    <int> <int> <int> <dbl>
##  1  2013     1     1 11.5 
##  2  2013     1     2 13.9 
##  3  2013     1     3 11.0 
##  4  2013     1     4  8.95
##  5  2013     1     5  5.73
##  6  2013     1     6  7.15
##  7  2013     1     7  5.42
##  8  2013     1     8  2.55
##  9  2013     1     9  2.28
## 10  2013     1    10  2.84
## # ℹ 355 more rows
not_cancelled <- flights %>% filter(!is.na(arr_delay))
avg_delay <- not_cancelled %>%
group_by(tailnum) %>%
summarise(mean_arr_delay = mean(arr_delay, na.rm = TRUE))
lowest_delay <- avg_delay %>% arrange(mean_arr_delay) %>% slice(1)
lowest_delay
## # A tibble: 1 × 2
##   tailnum mean_arr_delay
##   <chr>            <dbl>
## 1 N560AS             -53
not_cancelled %>% group_by(year, month, day) %>% summarise(
first = min(dep_time),
last = max(dep_time) )
## `summarise()` has grouped output by 'year', 'month'. You can override using the
## `.groups` argument.
## # A tibble: 365 × 5
## # Groups:   year, month [12]
##     year month   day first  last
##    <int> <int> <int> <int> <int>
##  1  2013     1     1   517  2356
##  2  2013     1     2    42  2354
##  3  2013     1     3    32  2349
##  4  2013     1     4    25  2358
##  5  2013     1     5    14  2357
##  6  2013     1     6    16  2355
##  7  2013     1     7    49  2359
##  8  2013     1     8   454  2351
##  9  2013     1     9     2  2252
## 10  2013     1    10     3  2320
## # ℹ 355 more rows
flights %>% group_by(month) %>% summarise(
prop_over_hour = mean(dep_delay > 60, na.rm = TRUE) ) %>%
arrange(desc(prop_over_hour))
## # A tibble: 12 × 2
##    month prop_over_hour
##    <int>          <dbl>
##  1     7         0.134 
##  2     6         0.128 
##  3    12         0.0942
##  4     4         0.0916
##  5     3         0.0837
##  6     5         0.0818
##  7     8         0.0796
##  8     2         0.0698
##  9     1         0.0688
## 10     9         0.0490
## 11    10         0.0469
## 12    11         0.0402
flights %>%
group_by(dest) %>%
summarise(num_carriers = n_distinct(carrier)) %>% arrange(desc(num_carriers))
## # A tibble: 105 × 2
##    dest  num_carriers
##    <chr>        <int>
##  1 ATL              7
##  2 BOS              7
##  3 CLT              7
##  4 ORD              7
##  5 TPA              7
##  6 AUS              6
##  7 DCA              6
##  8 DTW              6
##  9 IAD              6
## 10 MSP              6
## # ℹ 95 more rows
avg_arr_delay <- not_cancelled %>%
group_by(tailnum) %>%
summarise(avg_arr_delay = mean(arr_delay, na.rm = TRUE))
lowest_delay_tailnum <- avg_arr_delay %>% filter(avg_arr_delay == min(avg_arr_delay, na.rm = TRUE))
lowest_delay_tailnum
## # A tibble: 1 × 2
##   tailnum avg_arr_delay
##   <chr>           <dbl>
## 1 N560AS            -53
not_cancelled <- flights %>% 
filter(!is.na(arr_delay))
avg_arr_delay <- not_cancelled %>%
group_by(tailnum) %>%
summarise(avg_arr_delay = mean(arr_delay, na.rm = TRUE))
lowest_delay_tailnum <- avg_arr_delay %>% filter(avg_arr_delay == min(avg_arr_delay, na.rm = TRUE))
lowest_delay_tailnum
## # A tibble: 1 × 2
##   tailnum avg_arr_delay
##   <chr>           <dbl>
## 1 N560AS            -53