Data Frame Pada R

Assalamualaikum warahmatullahi wabarakatuh, Robbi Zidni Ilma Warzuqni Fahma, Aamiin Semoga Allah senantiasa memberkahi kita, dan menganugerahkan kepada kita, Ilmu yang bermanfaat. Dalam modul ini, teman-teman akan belajar Data Frame pada R.

Berbeda dengan matriks yang elemen-elemennya harus memiliki type data yang sama, data frame dapat berisikan elemen-elemen dengan type data yang berbeda. Dalam kehidupan sehari-hari kita akan lebih banyak menggunakan data frame daripada matriks. Data frame lebih relevan dengan banyak data yang ada.

Membuat Data Frame

Membuat DataFrame

nama <- c("Ana","Banu", "Cici", "Dido", "Erik")
tahun <- c(1992,1995,1993,1999,1994)
lahir <- data.frame(nama, tahun)
lahir
##   nama tahun
## 1  Ana  1992
## 2 Banu  1995
## 3 Cici  1993
## 4 Dido  1999
## 5 Erik  1994

Memanggil DataFrame Bawaan

mtcars 
##                      mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
## Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2

Mengenal Data Frame

#Melihat profil Data Frame
str(mtcars)
## 'data.frame':    32 obs. of  11 variables:
##  $ mpg : num  21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ...
##  $ cyl : num  6 6 4 6 8 6 8 4 4 6 ...
##  $ disp: num  160 160 108 258 360 ...
##  $ hp  : num  110 110 93 110 175 105 245 62 95 123 ...
##  $ drat: num  3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ...
##  $ wt  : num  2.62 2.88 2.32 3.21 3.44 ...
##  $ qsec: num  16.5 17 18.6 19.4 17 ...
##  $ vs  : num  0 0 1 1 0 1 0 1 1 1 ...
##  $ am  : num  1 1 1 0 0 0 0 0 0 0 ...
##  $ gear: num  4 4 4 3 3 3 3 4 4 4 ...
##  $ carb: num  4 4 1 1 2 1 4 2 2 4 ...
#Statistik Data Numerik pada Data Frame
summary(mtcars)
##       mpg             cyl             disp             hp       
##  Min.   :10.40   Min.   :4.000   Min.   : 71.1   Min.   : 52.0  
##  1st Qu.:15.43   1st Qu.:4.000   1st Qu.:120.8   1st Qu.: 96.5  
##  Median :19.20   Median :6.000   Median :196.3   Median :123.0  
##  Mean   :20.09   Mean   :6.188   Mean   :230.7   Mean   :146.7  
##  3rd Qu.:22.80   3rd Qu.:8.000   3rd Qu.:326.0   3rd Qu.:180.0  
##  Max.   :33.90   Max.   :8.000   Max.   :472.0   Max.   :335.0  
##       drat             wt             qsec             vs        
##  Min.   :2.760   Min.   :1.513   Min.   :14.50   Min.   :0.0000  
##  1st Qu.:3.080   1st Qu.:2.581   1st Qu.:16.89   1st Qu.:0.0000  
##  Median :3.695   Median :3.325   Median :17.71   Median :0.0000  
##  Mean   :3.597   Mean   :3.217   Mean   :17.85   Mean   :0.4375  
##  3rd Qu.:3.920   3rd Qu.:3.610   3rd Qu.:18.90   3rd Qu.:1.0000  
##  Max.   :4.930   Max.   :5.424   Max.   :22.90   Max.   :1.0000  
##        am              gear            carb      
##  Min.   :0.0000   Min.   :3.000   Min.   :1.000  
##  1st Qu.:0.0000   1st Qu.:3.000   1st Qu.:2.000  
##  Median :0.0000   Median :4.000   Median :2.000  
##  Mean   :0.4062   Mean   :3.688   Mean   :2.812  
##  3rd Qu.:1.0000   3rd Qu.:4.000   3rd Qu.:4.000  
##  Max.   :1.0000   Max.   :5.000   Max.   :8.000

Mengakses Data Frame

#Mendefinisikan Data Frame df
df<-mtcars
print(df)
##                      mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
## Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
#Mengakses kolom dengan nama kolom
pilih_kolom<-df$mpg
print(pilih_kolom)
##  [1] 21.0 21.0 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 17.8 16.4 17.3 15.2 10.4
## [16] 10.4 14.7 32.4 30.4 33.9 21.5 15.5 15.2 13.3 19.2 27.3 26.0 30.4 15.8 19.7
## [31] 15.0 21.4
#Mengakses kolom dengan indeks baris
pilih_baris<-df[1:5]
print(pilih_baris)
##                      mpg cyl  disp  hp drat
## Mazda RX4           21.0   6 160.0 110 3.90
## Mazda RX4 Wag       21.0   6 160.0 110 3.90
## Datsun 710          22.8   4 108.0  93 3.85
## Hornet 4 Drive      21.4   6 258.0 110 3.08
## Hornet Sportabout   18.7   8 360.0 175 3.15
## Valiant             18.1   6 225.0 105 2.76
## Duster 360          14.3   8 360.0 245 3.21
## Merc 240D           24.4   4 146.7  62 3.69
## Merc 230            22.8   4 140.8  95 3.92
## Merc 280            19.2   6 167.6 123 3.92
## Merc 280C           17.8   6 167.6 123 3.92
## Merc 450SE          16.4   8 275.8 180 3.07
## Merc 450SL          17.3   8 275.8 180 3.07
## Merc 450SLC         15.2   8 275.8 180 3.07
## Cadillac Fleetwood  10.4   8 472.0 205 2.93
## Lincoln Continental 10.4   8 460.0 215 3.00
## Chrysler Imperial   14.7   8 440.0 230 3.23
## Fiat 128            32.4   4  78.7  66 4.08
## Honda Civic         30.4   4  75.7  52 4.93
## Toyota Corolla      33.9   4  71.1  65 4.22
## Toyota Corona       21.5   4 120.1  97 3.70
## Dodge Challenger    15.5   8 318.0 150 2.76
## AMC Javelin         15.2   8 304.0 150 3.15
## Camaro Z28          13.3   8 350.0 245 3.73
## Pontiac Firebird    19.2   8 400.0 175 3.08
## Fiat X1-9           27.3   4  79.0  66 4.08
## Porsche 914-2       26.0   4 120.3  91 4.43
## Lotus Europa        30.4   4  95.1 113 3.77
## Ford Pantera L      15.8   8 351.0 264 4.22
## Ferrari Dino        19.7   6 145.0 175 3.62
## Maserati Bora       15.0   8 301.0 335 3.54
## Volvo 142E          21.4   4 121.0 109 4.11
#Mengakses kolom dengan indeks baris dan kolom
pilih_df<-df[1:5, 2:3]
print(pilih_df)
##                   cyl disp
## Mazda RX4           6  160
## Mazda RX4 Wag       6  160
## Datsun 710          4  108
## Hornet 4 Drive      6  258
## Hornet Sportabout   8  360
#Mengakses data dengan kriteria tertentu [misal cyl=6] (tunggal)
pilih_df1<-df[df[, "cyl"]==6,]
print(pilih_df1)
##                 mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4      21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag  21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## Hornet 4 Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## Valiant        18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## Merc 280       19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## Merc 280C      17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## Ferrari Dino   19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
#Mengakses data dengan kriteria tertentu [misal cyl=6 dan disp=160.0] (lebih dari satu)
pilih_df2<-df[df[, "cyl"]==6 & df[, "disp"]==160.0,]
print(pilih_df2)
##               mpg cyl disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4      21   6  160 110  3.9 2.620 16.46  0  1    4    4
## Mazda RX4 Wag  21   6  160 110  3.9 2.875 17.02  0  1    4    4
#Mengakses data dengan kriteria tertentu dan untukkolom tertentu
pilih_df3<-df[df[, "cyl"]==6 & df[, "disp"]==160.0, "wt"]
print(pilih_df3)
## [1] 2.620 2.875

Memodifikasi Data Frame

Menambah Kolom Baru

# Membuat Data Frame.
emp.data <- data.frame(
   emp_id = c (1:5), 
   emp_name = c("Ricki","Daan","Megi","Ryan","Budi"),
   salary = c(623.3,515.2,611.0,729.0,843.25), 
   
   start_date = as.Date(c("2012-01-01", "2013-09-23", "2014-11-15", "2014-05-11",
      "2015-03-27")),
   stringsAsFactors = FALSE
)

# Menambah kolom Departemen.
emp.data$dept <- c("IT","Operations","IT","HR","Finance")
v <- emp.data
print(v)
##   emp_id emp_name salary start_date       dept
## 1      1    Ricki 623.30 2012-01-01         IT
## 2      2     Daan 515.20 2013-09-23 Operations
## 3      3     Megi 611.00 2014-11-15         IT
## 4      4     Ryan 729.00 2014-05-11         HR
## 5      5     Budi 843.25 2015-03-27    Finance

Menambah Baris Baru

# Membuat Data Frame.
emp.data <- data.frame(
   emp_id = c (1:5), 
   emp_name = c("Ricki","Daan","Megi","Ryan","Budi"),
   salary = c(623.3,515.2,611.0,729.0,843.25), 
   
   start_date = as.Date(c("2012-01-01", "2013-09-23", "2014-11-15", "2014-05-11",
      "2015-03-27")),
   dept = c("IT","Operations","IT","HR","Finance"),
   stringsAsFactors = FALSE
)
# Membuat Data Frame kedua
emp.newdata <-  data.frame(
   emp_id = c (6:8), 
   emp_name = c("Rasmi","Pranab","Tusar"),
   salary = c(578.0,722.5,632.8), 
   start_date = as.Date(c("2013-05-21","2013-07-30","2014-06-17")),
   dept = c("IT","Operations","Finance"),
   stringsAsFactors = FALSE
)

# Menambah baris Data.
emp.finaldata <- rbind(emp.data,emp.newdata)
print(emp.finaldata)
##   emp_id emp_name salary start_date       dept
## 1      1    Ricki 623.30 2012-01-01         IT
## 2      2     Daan 515.20 2013-09-23 Operations
## 3      3     Megi 611.00 2014-11-15         IT
## 4      4     Ryan 729.00 2014-05-11         HR
## 5      5     Budi 843.25 2015-03-27    Finance
## 6      6    Rasmi 578.00 2013-05-21         IT
## 7      7   Pranab 722.50 2013-07-30 Operations
## 8      8    Tusar 632.80 2014-06-17    Finance

Mengurutkan Isi Data Frame

# Membuat Data Frame.
df<-mtcars
print(df)
# Urutkan berdasar kolom mpg
newdata1 <- df[order(mpg),]
print(newdata1)
# Urutkan berdasar kolom mpg and cyl
newdata2 <- df[order(mpg, cyl),]
print(newdata2)
#Urutkan berdasar kolom mpg (menaik) and cyl (menurun)
newdata3 <- df[order(mpg, -cyl),]
print(newdata3)

Menggabungkan Dua Data Frame

Syntax untuk menggabungkan dua Data Frame

merge(x, y, by.x = x, by.y = y)
Argumen:
-x: Data Frame Utama
-y: Data Frame yang akan digabungkan
-by.x: Kolom yang digunakan untuk menggabungkan dalam data frame x. Kolom x untuk digabungkan
-by.y: Kolom yang digunakan untuk menggabungkan dalam data frame y. Kolom y untuk digabungkan

Contoh

# Data Frame Utama {Producers}
producers <- data.frame(   
    surname =  c("Spielberg","Scorsese","Hitchcock","Tarantino","Polanski"),    
    nationality = c("US","US","UK","US","Poland"),    
    stringsAsFactors=FALSE)

# Data Frame yang akan digabungkan
movies <- data.frame(    
    surname = c("Spielberg",
        "Scorsese",
                "Hitchcock",
                "Hitchcock",
                "Spielberg",
                "Tarantino",
                "Polanski"),    
    title = c("Super 8",
            "Taxi Driver",
            "Psycho",
            "North by Northwest",
            "Catch Me If You Can",
            "Reservoir Dogs","Chinatown"),                
            stringsAsFactors=FALSE)

# Menggabungkan Dua Data Frame 
m1 <- merge(producers, movies, by.x = "surname")
m1
##     surname nationality               title
## 1 Hitchcock          UK              Psycho
## 2 Hitchcock          UK  North by Northwest
## 3  Polanski      Poland           Chinatown
## 4  Scorsese          US         Taxi Driver
## 5 Spielberg          US             Super 8
## 6 Spielberg          US Catch Me If You Can
## 7 Tarantino          US      Reservoir Dogs
dim(m1)
## [1] 7 3
# Mengganti nama kolom "movies" 
colnames(movies)[colnames(movies) == 'surname'] <- 'name'

# Menggabungkan dengan kata kunci lainnya
m2 <- merge(producers, movies, by.x = "surname", by.y = "name")
head(m2)
##     surname nationality               title
## 1 Hitchcock          UK              Psycho
## 2 Hitchcock          UK  North by Northwest
## 3  Polanski      Poland           Chinatown
## 4  Scorsese          US         Taxi Driver
## 5 Spielberg          US             Super 8
## 6 Spielberg          US Catch Me If You Can
# Menambah data producers
add_producer <-  c('Lucas', 'US')
producers <- rbind(producers, add_producer)

# Melakukan gabungan parsial
m3 <-merge(producers, movies, by.x = "surname", by.y = "name", all.x = TRUE)
m3
##     surname nationality               title
## 1 Hitchcock          UK              Psycho
## 2 Hitchcock          UK  North by Northwest
## 3     Lucas          US                <NA>
## 4  Polanski      Poland           Chinatown
## 5  Scorsese          US         Taxi Driver
## 6 Spielberg          US             Super 8
## 7 Spielberg          US Catch Me If You Can
## 8 Tarantino          US      Reservoir Dogs