How to extract unique values in multiple columns in an R data frame using a single line code?

To extract unique values in multiple columns in an R data frame, we first need to create a vector of the column values but for that we would need to read the columns in matrix form. After that we can simply unique function for the extraction. To understand how it works check out the below examples.

Consider the below data frame −

Example

 Live Demo

x1<-rpois(20,2)
x2<-rpois(20,5)
x3<-rpois(20,2)
df1<-data.frame(x1,x2,x3)
df1

Output

   x1 x2 x3
1  1  4  3
2  2  3  2
3  1  6  1
4  1  6  1
5  2  4  2
6  2  4  0
7  1  5  1
8  3  5  2
9  3  7  3
10 1  2  2
11 2  6  3
12 2  3  1
13 3  6  0
14 2  4  7
15 1  6  1
16 0  4  0
17 1  2  2
18 4  3  1
19 1  4  1
20 3  7  2

Extracting unique values in df1 −

Example

df1<-as.vector(as.matrix(df1))
unique(df1)

Output

[1] 1 2 3 0 4 6 5 7

Example

 Live Demo

y1<-rpois(20,10)
y2<-rpois(20,20)
y3<-rpois(20,5)
df2<-data.frame(y1,y2,y3)
df2

Output

   y1  y2  y3
1  8   24  5
2  5   19  2
3  8   17  1
4  10  21  5
5  8   27  3
6  12 14   5
7  8   19  3
8  11  26  10
9  11  25  5
10 6   20  7
11 4   26  3
12 7   21  6
13 14  21  3
14 11  18  7
15 11  13  6
16 7  17   5
17 9  21   7
18 5  20   6
19 16 24   7
20 8  14  1

Extracting unique values in df2 −

Example

df2<-as.vector(as.matrix(df2))
unique(df2)

Output

[1] 8 5 10 12 11 6 4 7 14 9 16 24 19 17 21 27 26 25 20 18 13 2 1 3

Nizamuddin Siddiqui

Updated on 06-Feb-2021 08:20:16

• Related Questions & Answers
• How to convert multiple columns into single column in an R data frame?
• How to extract a single column of an R data frame as a data frame?
• How to extract unique combination of rows in an R data frame?
• How to make all values in an R data frame unique?
• How to extract columns of a data frame in R using dplyr package?
• How to remove outliers from multiple boxplots created with the help of boxplot function for columns of a data frame using single line code in R?
• How to change a data frame with comma separated values in columns to multiple columns in R?
• How to extract data frame columns stored in a list in R?
• How to extract only factor columns name from an R data frame?
• How to multiply row values in a data frame having multiple rows with single row data frame in R?
• How to convert columns of an R data frame into a single vector?
• How to find the unique values in a column of an R data frame?
• Extract columns with a string in column name of an R data frame.
• How to delete different rows and columns of a matrix using a single line code in R?
• How to extract unique combinations of two or more variables in an R data frame?