knitr::opts_chunk$set(echo = TRUE)R checks for duplicates across rows through the duplicated() function.
Let’s identify dupliccates inthe data below
x1 <- c(2, 4, 5, 6)
x2 <- c(2, 3, 5, 6)
x3 <- c(2, 4, 5, 6)
x4 <- c(2, 4, 5, 6)
df <- data.frame(rbind(x1, x2, x3, x4))
df## X1 X2 X3 X4
## x1 2 4 5 6
## x2 2 3 5 6
## x3 2 4 5 6
## x4 2 4 5 6Let’s now find duplicated rows in our dataset
duplicated_rows <- df[duplicated(df),]we print out the variable to see if we have any duplicated rows
duplicated_rows ## X1 X2 X3 X4
## x3 2 4 5 6
## x4 2 4 5 6We have two duplicated rows
Removing these duplicated rows in the dataset or showing these unique items and assigning to a variable unique_items below
unique_items <- df[!duplicated(df), ]
unique_items## X1 X2 X3 X4
## x1 2 4 5 6
## x2 2 3 5 6we can also remove duplicated rows in the dataset or show the unique items using the unique() function
unique_items2 <- unique(df)
unique_items2## X1 X2 X3 X4
## x1 2 4 5 6
## x2 2 3 5 6We are going to display and delete the only duplicate records in the iris dataset below:
head(iris)## Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1 5.1 3.5 1.4 0.2 setosa
## 2 4.9 3.0 1.4 0.2 setosa
## 3 4.7 3.2 1.3 0.2 setosa
## 4 4.6 3.1 1.5 0.2 setosa
## 5 5.0 3.6 1.4 0.2 setosa
## 6 5.4 3.9 1.7 0.4 setosadim(iris)## [1] 150 5iris_duplicated_rows <- iris[duplicated(iris),]
iris_duplicated_rows## Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 143 5.8 2.7 5.1 1.9 virginicaWe only have one duplicated row, so going to drop this duplicated row
unique(iris)## Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1 5.1 3.5 1.4 0.2 setosa
## 2 4.9 3.0 1.4 0.2 setosa
## 3 4.7 3.2 1.3 0.2 setosa
## 4 4.6 3.1 1.5 0.2 setosa
## 5 5.0 3.6 1.4 0.2 setosa
## 6 5.4 3.9 1.7 0.4 setosa
## 7 4.6 3.4 1.4 0.3 setosa
## 8 5.0 3.4 1.5 0.2 setosa
## 9 4.4 2.9 1.4 0.2 setosa
## 10 4.9 3.1 1.5 0.1 setosa
## 11 5.4 3.7 1.5 0.2 setosa
## 12 4.8 3.4 1.6 0.2 setosa
## 13 4.8 3.0 1.4 0.1 setosa
## 14 4.3 3.0 1.1 0.1 setosa
## 15 5.8 4.0 1.2 0.2 setosa
## 16 5.7 4.4 1.5 0.4 setosa
## 17 5.4 3.9 1.3 0.4 setosa
## 18 5.1 3.5 1.4 0.3 setosa
## 19 5.7 3.8 1.7 0.3 setosa
## 20 5.1 3.8 1.5 0.3 setosa
## 21 5.4 3.4 1.7 0.2 setosa
## 22 5.1 3.7 1.5 0.4 setosa
## 23 4.6 3.6 1.0 0.2 setosa
## 24 5.1 3.3 1.7 0.5 setosa
## 25 4.8 3.4 1.9 0.2 setosa
## 26 5.0 3.0 1.6 0.2 setosa
## 27 5.0 3.4 1.6 0.4 setosa
## 28 5.2 3.5 1.5 0.2 setosa
## 29 5.2 3.4 1.4 0.2 setosa
## 30 4.7 3.2 1.6 0.2 setosa
## 31 4.8 3.1 1.6 0.2 setosa
## 32 5.4 3.4 1.5 0.4 setosa
## 33 5.2 4.1 1.5 0.1 setosa
## 34 5.5 4.2 1.4 0.2 setosa
## 35 4.9 3.1 1.5 0.2 setosa
## 36 5.0 3.2 1.2 0.2 setosa
## 37 5.5 3.5 1.3 0.2 setosa
## 38 4.9 3.6 1.4 0.1 setosa
## 39 4.4 3.0 1.3 0.2 setosa
## 40 5.1 3.4 1.5 0.2 setosa
## 41 5.0 3.5 1.3 0.3 setosa
## 42 4.5 2.3 1.3 0.3 setosa
## 43 4.4 3.2 1.3 0.2 setosa
## 44 5.0 3.5 1.6 0.6 setosa
## 45 5.1 3.8 1.9 0.4 setosa
## 46 4.8 3.0 1.4 0.3 setosa
## 47 5.1 3.8 1.6 0.2 setosa
## 48 4.6 3.2 1.4 0.2 setosa
## 49 5.3 3.7 1.5 0.2 setosa
## 50 5.0 3.3 1.4 0.2 setosa
## 51 7.0 3.2 4.7 1.4 versicolor
## 52 6.4 3.2 4.5 1.5 versicolor
## 53 6.9 3.1 4.9 1.5 versicolor
## 54 5.5 2.3 4.0 1.3 versicolor
## 55 6.5 2.8 4.6 1.5 versicolor
## 56 5.7 2.8 4.5 1.3 versicolor
## 57 6.3 3.3 4.7 1.6 versicolor
## 58 4.9 2.4 3.3 1.0 versicolor
## 59 6.6 2.9 4.6 1.3 versicolor
## 60 5.2 2.7 3.9 1.4 versicolor
## 61 5.0 2.0 3.5 1.0 versicolor
## 62 5.9 3.0 4.2 1.5 versicolor
## 63 6.0 2.2 4.0 1.0 versicolor
## 64 6.1 2.9 4.7 1.4 versicolor
## 65 5.6 2.9 3.6 1.3 versicolor
## 66 6.7 3.1 4.4 1.4 versicolor
## 67 5.6 3.0 4.5 1.5 versicolor
## 68 5.8 2.7 4.1 1.0 versicolor
## 69 6.2 2.2 4.5 1.5 versicolor
## 70 5.6 2.5 3.9 1.1 versicolor
## 71 5.9 3.2 4.8 1.8 versicolor
## 72 6.1 2.8 4.0 1.3 versicolor
## 73 6.3 2.5 4.9 1.5 versicolor
## 74 6.1 2.8 4.7 1.2 versicolor
## 75 6.4 2.9 4.3 1.3 versicolor
## 76 6.6 3.0 4.4 1.4 versicolor
## 77 6.8 2.8 4.8 1.4 versicolor
## 78 6.7 3.0 5.0 1.7 versicolor
## 79 6.0 2.9 4.5 1.5 versicolor
## 80 5.7 2.6 3.5 1.0 versicolor
## 81 5.5 2.4 3.8 1.1 versicolor
## 82 5.5 2.4 3.7 1.0 versicolor
## 83 5.8 2.7 3.9 1.2 versicolor
## 84 6.0 2.7 5.1 1.6 versicolor
## 85 5.4 3.0 4.5 1.5 versicolor
## 86 6.0 3.4 4.5 1.6 versicolor
## 87 6.7 3.1 4.7 1.5 versicolor
## 88 6.3 2.3 4.4 1.3 versicolor
## 89 5.6 3.0 4.1 1.3 versicolor
## 90 5.5 2.5 4.0 1.3 versicolor
## 91 5.5 2.6 4.4 1.2 versicolor
## 92 6.1 3.0 4.6 1.4 versicolor
## 93 5.8 2.6 4.0 1.2 versicolor
## 94 5.0 2.3 3.3 1.0 versicolor
## 95 5.6 2.7 4.2 1.3 versicolor
## 96 5.7 3.0 4.2 1.2 versicolor
## 97 5.7 2.9 4.2 1.3 versicolor
## 98 6.2 2.9 4.3 1.3 versicolor
## 99 5.1 2.5 3.0 1.1 versicolor
## 100 5.7 2.8 4.1 1.3 versicolor
## 101 6.3 3.3 6.0 2.5 virginica
## 102 5.8 2.7 5.1 1.9 virginica
## 103 7.1 3.0 5.9 2.1 virginica
## 104 6.3 2.9 5.6 1.8 virginica
## 105 6.5 3.0 5.8 2.2 virginica
## 106 7.6 3.0 6.6 2.1 virginica
## 107 4.9 2.5 4.5 1.7 virginica
## 108 7.3 2.9 6.3 1.8 virginica
## 109 6.7 2.5 5.8 1.8 virginica
## 110 7.2 3.6 6.1 2.5 virginica
## 111 6.5 3.2 5.1 2.0 virginica
## 112 6.4 2.7 5.3 1.9 virginica
## 113 6.8 3.0 5.5 2.1 virginica
## 114 5.7 2.5 5.0 2.0 virginica
## 115 5.8 2.8 5.1 2.4 virginica
## 116 6.4 3.2 5.3 2.3 virginica
## 117 6.5 3.0 5.5 1.8 virginica
## 118 7.7 3.8 6.7 2.2 virginica
## 119 7.7 2.6 6.9 2.3 virginica
## 120 6.0 2.2 5.0 1.5 virginica
## 121 6.9 3.2 5.7 2.3 virginica
## 122 5.6 2.8 4.9 2.0 virginica
## 123 7.7 2.8 6.7 2.0 virginica
## 124 6.3 2.7 4.9 1.8 virginica
## 125 6.7 3.3 5.7 2.1 virginica
## 126 7.2 3.2 6.0 1.8 virginica
## 127 6.2 2.8 4.8 1.8 virginica
## 128 6.1 3.0 4.9 1.8 virginica
## 129 6.4 2.8 5.6 2.1 virginica
## 130 7.2 3.0 5.8 1.6 virginica
## 131 7.4 2.8 6.1 1.9 virginica
## 132 7.9 3.8 6.4 2.0 virginica
## 133 6.4 2.8 5.6 2.2 virginica
## 134 6.3 2.8 5.1 1.5 virginica
## 135 6.1 2.6 5.6 1.4 virginica
## 136 7.7 3.0 6.1 2.3 virginica
## 137 6.3 3.4 5.6 2.4 virginica
## 138 6.4 3.1 5.5 1.8 virginica
## 139 6.0 3.0 4.8 1.8 virginica
## 140 6.9 3.1 5.4 2.1 virginica
## 141 6.7 3.1 5.6 2.4 virginica
## 142 6.9 3.1 5.1 2.3 virginica
## 144 6.8 3.2 5.9 2.3 virginica
## 145 6.7 3.3 5.7 2.5 virginica
## 146 6.7 3.0 5.2 2.3 virginica
## 147 6.3 2.5 5.0 1.9 virginica
## 148 6.5 3.0 5.2 2.0 virginica
## 149 6.2 3.4 5.4 2.3 virginica
## 150 5.9 3.0 5.1 1.8 virginicaOur row count has changed from 150 to 149 meaning the duplicated row has been dropped
Will check for duplicates and drop them in the following dataset
library("data.table")## Warning: package 'data.table' was built under R version 4.1.2video_games <- fread('http://bit.ly/VideoGamesDataset')Get a grimpse of our dataset
head(video_games)## V1 V2 V3 V4 V5
## 1: 151603712 The Elder Scrolls V Skyrim purchase 1.0 0
## 2: 151603712 The Elder Scrolls V Skyrim play 273.0 0
## 3: 151603712 Fallout 4 purchase 1.0 0
## 4: 151603712 Fallout 4 play 87.0 0
## 5: 151603712 Spore purchase 1.0 0
## 6: 151603712 Spore play 14.9 0Number of rows and columns
dim(video_games)## [1] 200000 5Now we check for duplicates
Video_game_duplicated <- video_games[duplicated(video_games),]
Video_game_duplicated## V1 V2 V3 V4 V5
## 1: 11373749 Sid Meier's Civilization IV purchase 1 0
## 2: 11373749 Sid Meier's Civilization IV Beyond the Sword purchase 1 0
## 3: 11373749 Sid Meier's Civilization IV Warlords purchase 1 0
## 4: 56038151 Grand Theft Auto San Andreas purchase 1 0
## 5: 56038151 Grand Theft Auto Vice City purchase 1 0
## ---
## 703: 39146470 Sid Meier's Civilization IV Warlords purchase 1 0
## 704: 48666962 Crysis 2 purchase 1 0
## 705: 112845094 Grand Theft Auto San Andreas purchase 1 0
## 706: 112845094 Grand Theft Auto Vice City purchase 1 0
## 707: 112845094 Grand Theft Auto III purchase 1 0We have 707 rows duplicated, we are going to drop them
unique(video_games)## V1 V2 V3 V4 V5
## 1: 151603712 The Elder Scrolls V Skyrim purchase 1.0 0
## 2: 151603712 The Elder Scrolls V Skyrim play 273.0 0
## 3: 151603712 Fallout 4 purchase 1.0 0
## 4: 151603712 Fallout 4 play 87.0 0
## 5: 151603712 Spore purchase 1.0 0
## ---
## 199289: 128470551 Titan Souls play 1.5 0
## 199290: 128470551 Grand Theft Auto Vice City purchase 1.0 0
## 199291: 128470551 Grand Theft Auto Vice City play 1.5 0
## 199292: 128470551 RUSH purchase 1.0 0
## 199293: 128470551 RUSH play 1.4 0