Disini saya akan mencoba belajar tentang “Data Wrangling”. “Data Wrangling” adalah suatu usaha agar data yang saya miliki menjadi bentuk yang dapat digunakan/berguna untuk melakukan “vizualitation” dan “modelling”. Pada bagian ini saya akan belajar tentang merapikan data menggunakan dplyr. Sebagain pernah dicoba-coba pada bagian dplyr.
library(tidyverse)
# agar dapat menggunakan dataset yang ada pada package ini
library(nycflights13)
Dataset yang digunakan adalah sebagai berikut:
airlines
## # A tibble: 16 x 2
## carrier name
## <chr> <chr>
## 1 9E Endeavor Air Inc.
## 2 AA American Airlines Inc.
## 3 AS Alaska Airlines Inc.
## 4 B6 JetBlue Airways
## 5 DL Delta Air Lines Inc.
## 6 EV ExpressJet Airlines Inc.
## 7 F9 Frontier Airlines Inc.
## 8 FL AirTran Airways Corporation
## 9 HA Hawaiian Airlines Inc.
## 10 MQ Envoy Air
## 11 OO SkyWest Airlines Inc.
## 12 UA United Air Lines Inc.
## 13 US US Airways Inc.
## 14 VX Virgin America
## 15 WN Southwest Airlines Co.
## 16 YV Mesa Airlines Inc.
airports
## # A tibble: 1,458 x 8
## faa name lat lon alt tz dst tzone
## <chr> <chr> <dbl> <dbl> <dbl> <dbl> <chr> <chr>
## 1 04G Lansdowne Airport 41.1 -80.6 1044 -5 A America/New_Yo~
## 2 06A Moton Field Municipal A~ 32.5 -85.7 264 -6 A America/Chicago
## 3 06C Schaumburg Regional 42.0 -88.1 801 -6 A America/Chicago
## 4 06N Randall Airport 41.4 -74.4 523 -5 A America/New_Yo~
## 5 09J Jekyll Island Airport 31.1 -81.4 11 -5 A America/New_Yo~
## 6 0A9 Elizabethton Municipal ~ 36.4 -82.2 1593 -5 A America/New_Yo~
## 7 0G6 Williams County Airport 41.5 -84.5 730 -5 A America/New_Yo~
## 8 0G7 Finger Lakes Regional A~ 42.9 -76.8 492 -5 A America/New_Yo~
## 9 0P2 Shoestring Aviation Air~ 39.8 -76.6 1000 -5 U America/New_Yo~
## 10 0S9 Jefferson County Intl 48.1 -123. 108 -8 A America/Los_An~
## # ... with 1,448 more rows
planes
## # A tibble: 3,322 x 9
## tailnum year type manufacturer model engines seats speed engine
## <chr> <int> <chr> <chr> <chr> <int> <int> <int> <chr>
## 1 N10156 2004 Fixed wing m~ EMBRAER EMB-1~ 2 55 NA Turbo-~
## 2 N102UW 1998 Fixed wing m~ AIRBUS INDUST~ A320-~ 2 182 NA Turbo-~
## 3 N103US 1999 Fixed wing m~ AIRBUS INDUST~ A320-~ 2 182 NA Turbo-~
## 4 N104UW 1999 Fixed wing m~ AIRBUS INDUST~ A320-~ 2 182 NA Turbo-~
## 5 N10575 2002 Fixed wing m~ EMBRAER EMB-1~ 2 55 NA Turbo-~
## 6 N105UW 1999 Fixed wing m~ AIRBUS INDUST~ A320-~ 2 182 NA Turbo-~
## 7 N107US 1999 Fixed wing m~ AIRBUS INDUST~ A320-~ 2 182 NA Turbo-~
## 8 N108UW 1999 Fixed wing m~ AIRBUS INDUST~ A320-~ 2 182 NA Turbo-~
## 9 N109UW 1999 Fixed wing m~ AIRBUS INDUST~ A320-~ 2 182 NA Turbo-~
## 10 N110UW 1999 Fixed wing m~ AIRBUS INDUST~ A320-~ 2 182 NA Turbo-~
## # ... with 3,312 more rows
weather
## # A tibble: 26,115 x 15
## origin year month day hour temp dewp humid wind_dir wind_speed
## <chr> <int> <int> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 EWR 2013 1 1 1 39.0 26.1 59.4 270 10.4
## 2 EWR 2013 1 1 2 39.0 27.0 61.6 250 8.06
## 3 EWR 2013 1 1 3 39.0 28.0 64.4 240 11.5
## 4 EWR 2013 1 1 4 39.9 28.0 62.2 250 12.7
## 5 EWR 2013 1 1 5 39.0 28.0 64.4 260 12.7
## 6 EWR 2013 1 1 6 37.9 28.0 67.2 240 11.5
## 7 EWR 2013 1 1 7 39.0 28.0 64.4 240 15.0
## 8 EWR 2013 1 1 8 39.9 28.0 62.2 250 10.4
## 9 EWR 2013 1 1 9 39.9 28.0 62.2 260 15.0
## 10 EWR 2013 1 1 10 41 28.0 59.6 260 13.8
## # ... with 26,105 more rows, and 5 more variables: wind_gust <dbl>,
## # precip <dbl>, pressure <dbl>, visib <dbl>, time_hour <dttm>
flights
## # A tibble: 336,776 x 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
## # ... with 336,766 more rows, and 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>
Key adalah variabel atau set variabel yang secara unik mengidentifikasi pengamatan. Ada dua jenis “key”, yaitu “Primay Key” dan “Foreign Key”. Contoh “Primary Key”, setiap pesawat adalah teridentifikasi unik jika dilihat dari nomer ekor(nomer registrasi). Terlihat bahwa tidak ada pesawat yang memiliki nomor ekor (“tailnum”) lebih dari satu.Tailnum adalah “Primary Key”.
planes%>%
count(tailnum)%>%
filter(n>1)
## # A tibble: 0 x 2
## # ... with 2 variables: tailnum <chr>, n <int>
Primary Key juga bisa dalam kombinasi beberapa variabel.
weather%>%
count(year,month,day,hour,origin,temp)%>%
filter(n>1)
## # A tibble: 0 x 7
## # ... with 7 variables: year <int>, month <int>, day <int>, hour <int>,
## # origin <chr>, temp <dbl>, n <int>
Namun terkadang juga “key” tidak mengidentifikasi secara unik pengamatan pada dataset tersebut, namun secara unik mengidentifikasikan secara unik pada dataset yang lain. Hal ini disebut “Foreign Key”. Contoh pada dataset flights, tailnum bukan unik pada dataset ini namun merupakan unik pada dataset plane.
flights%>%
count(tailnum)%>%
filter(n>1)
## # A tibble: 3,873 x 2
## tailnum n
## <chr> <int>
## 1 D942DN 4
## 2 N0EGMQ 371
## 3 N10156 153
## 4 N102UW 48
## 5 N103US 46
## 6 N104UW 47
## 7 N10575 289
## 8 N105UW 45
## 9 N107US 41
## 10 N108UW 60
## # ... with 3,863 more rows
Misal saya ingin menambahkan nama pesawat pada dataset flights. Dan disini saya hanya ingin melihat variabel (year, month, day, hour,tailnum,carrier)
flights%>%
select(year:day, hour,tailnum,carrier)%>%
left_join(airlines, by="carrier")
## # A tibble: 336,776 x 7
## year month day hour tailnum carrier name
## <int> <int> <int> <dbl> <chr> <chr> <chr>
## 1 2013 1 1 5 N14228 UA United Air Lines Inc.
## 2 2013 1 1 5 N24211 UA United Air Lines Inc.
## 3 2013 1 1 5 N619AA AA American Airlines Inc.
## 4 2013 1 1 5 N804JB B6 JetBlue Airways
## 5 2013 1 1 6 N668DN DL Delta Air Lines Inc.
## 6 2013 1 1 5 N39463 UA United Air Lines Inc.
## 7 2013 1 1 6 N516JB B6 JetBlue Airways
## 8 2013 1 1 6 N829AS EV ExpressJet Airlines Inc.
## 9 2013 1 1 6 N593JB B6 JetBlue Airways
## 10 2013 1 1 6 N3ALAA AA American Airlines Inc.
## # ... with 336,766 more rows
Hasilnya samadengan yang diatas. Carrier adalah “Key”.
flights%>%
select(year:day, hour,tailnum,carrier)%>%
mutate(name = airlines$name[match(carrier, airlines$carrier)])
## # A tibble: 336,776 x 7
## year month day hour tailnum carrier name
## <int> <int> <int> <dbl> <chr> <chr> <chr>
## 1 2013 1 1 5 N14228 UA United Air Lines Inc.
## 2 2013 1 1 5 N24211 UA United Air Lines Inc.
## 3 2013 1 1 5 N619AA AA American Airlines Inc.
## 4 2013 1 1 5 N804JB B6 JetBlue Airways
## 5 2013 1 1 6 N668DN DL Delta Air Lines Inc.
## 6 2013 1 1 5 N39463 UA United Air Lines Inc.
## 7 2013 1 1 6 N516JB B6 JetBlue Airways
## 8 2013 1 1 6 N829AS EV ExpressJet Airlines Inc.
## 9 2013 1 1 6 N593JB B6 JetBlue Airways
## 10 2013 1 1 6 N3ALAA AA American Airlines Inc.
## # ... with 336,766 more rows
Contoh Join
x<-tribble(
~key, ~val_x,
1,"x1",
2,"x2",
3,"x3"
)
x
## # A tibble: 3 x 2
## key val_x
## <dbl> <chr>
## 1 1 x1
## 2 2 x2
## 3 3 x3
y<-tribble(
~key, ~val_y,
1,"y1",
2,"y2",
4,"y3"
)
y
## # A tibble: 3 x 2
## key val_y
## <dbl> <chr>
## 1 1 y1
## 2 2 y2
## 3 4 y3
x%>%inner_join(y, by="key")
## # A tibble: 2 x 3
## key val_x val_y
## <dbl> <chr> <chr>
## 1 1 x1 y1
## 2 2 x2 y2
x%>%left_join(y, by='key')
## # A tibble: 3 x 3
## key val_x val_y
## <dbl> <chr> <chr>
## 1 1 x1 y1
## 2 2 x2 y2
## 3 3 x3 <NA>
x%>%right_join(y, by='key')
## # A tibble: 3 x 3
## key val_x val_y
## <dbl> <chr> <chr>
## 1 1 x1 y1
## 2 2 x2 y2
## 3 4 <NA> y3
x%>%full_join(y, by='key')
## # A tibble: 4 x 3
## key val_x val_y
## <dbl> <chr> <chr>
## 1 1 x1 y1
## 2 2 x2 y2
## 3 3 x3 <NA>
## 4 4 <NA> y3
Contoh Join pada Dataset
flights%>%
left_join(weather)
## Joining, by = c("year", "month", "day", "origin", "hour", "time_hour")
## # A tibble: 336,776 x 28
## 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
## # ... with 336,766 more rows, and 20 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>,
## # temp <dbl>, dewp <dbl>, humid <dbl>, wind_dir <dbl>, wind_speed <dbl>,
## # wind_gust <dbl>, precip <dbl>, pressure <dbl>, visib <dbl>
Dest adalah “Key Foreign” pada flights, karena tailnum adalah “Key” pada airports, namun namanya adalah faa.
flights%>%
left_join(airports, c("dest"="faa"))
## # A tibble: 336,776 x 26
## 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
## # ... with 336,766 more rows, and 18 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>,
## # name <chr>, lat <dbl>, lon <dbl>, alt <dbl>, tz <dbl>, dst <chr>,
## # tzone <chr>
Top 10 Destination
top_dest<-flights%>%
count(dest, sort = T)%>%
head(10)
top_dest
## # A tibble: 10 x 2
## dest n
## <chr> <int>
## 1 ORD 17283
## 2 ATL 17215
## 3 LAX 16174
## 4 BOS 15508
## 5 MCO 14082
## 6 CLT 14064
## 7 SFO 13331
## 8 FLL 12055
## 9 MIA 11728
## 10 DCA 9705
Penerbangan ke top 10 destination
flights%>%
filter(dest%in%top_dest$dest)
## # A tibble: 141,145 x 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 1 542 540 2 923 850
## 2 2013 1 1 554 600 -6 812 837
## 3 2013 1 1 554 558 -4 740 728
## 4 2013 1 1 555 600 -5 913 854
## 5 2013 1 1 557 600 -3 838 846
## 6 2013 1 1 558 600 -2 753 745
## 7 2013 1 1 558 600 -2 924 917
## 8 2013 1 1 558 600 -2 923 937
## 9 2013 1 1 559 559 0 702 706
## 10 2013 1 1 600 600 0 851 858
## # ... with 141,135 more rows, and 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>
Semijoin hanya menghubungkan dua tebel yang baris table1nya cocok dengan table2 (sama seperti diatas)
flights%>%
semi_join(top_dest)
## Joining, by = "dest"
## # A tibble: 141,145 x 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 1 542 540 2 923 850
## 2 2013 1 1 554 600 -6 812 837
## 3 2013 1 1 554 558 -4 740 728
## 4 2013 1 1 555 600 -5 913 854
## 5 2013 1 1 557 600 -3 838 846
## 6 2013 1 1 558 600 -2 753 745
## 7 2013 1 1 558 600 -2 924 917
## 8 2013 1 1 558 600 -2 923 937
## 9 2013 1 1 559 559 0 702 706
## 10 2013 1 1 600 600 0 851 858
## # ... with 141,135 more rows, and 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>
Tambahan
Set Operations
df1<-tribble(
~a,~b,
1,1,
2,1
)
df1
## # A tibble: 2 x 2
## a b
## <dbl> <dbl>
## 1 1 1
## 2 2 1
df2<-tribble(
~a,~b,
1,1,
1,2
)
df2
## # A tibble: 2 x 2
## a b
## <dbl> <dbl>
## 1 1 1
## 2 1 2
intersect(df1,df2)
## # A tibble: 1 x 2
## a b
## <dbl> <dbl>
## 1 1 1
union(df1,df2)
## # A tibble: 3 x 2
## a b
## <dbl> <dbl>
## 1 1 1
## 2 2 1
## 3 1 2
setdiff(df1,df2)
## # A tibble: 1 x 2
## a b
## <dbl> <dbl>
## 1 2 1
setdiff(df2,df1)
## # A tibble: 1 x 2
## a b
## <dbl> <dbl>
## 1 1 2