How to Change Row Names in R (With Examples)


You can use the row.names() function to quickly get and set the row names of a data frame in R.

This tutorial provides several examples of how to use this function in practice on the built-in mtcars dataset in R:

#view first six rows of mtcars
head(mtcars)

                   mpg cyl disp  hp drat    wt  qsec vs am gear carb
Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

How to Get Row Names

You can use the following syntax to view the first few row names of the mtcars data frame:

#view first six row names of mtcars
head(row.names(mtcars))

[1] "Mazda RX4"         "Mazda RX4 Wag"     "Datsun 710"       
[4] "Hornet 4 Drive"    "Hornet Sportabout" "Valiant" 

How to Change One Row Name

You can use the following syntax to change on specific row name:

#change the row name called Datsun710 to 710
row.names(mtcars)[row.names(mtcars) == "Datsun 710"] <- "710"

#view first six row names of mtcars 
head(mtcars)

                   mpg cyl disp  hp drat    wt  qsec vs am gear carb
Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
710               22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

How to Change All Row Names

You can use the following syntax to change all of the row names to a list of integers starting at 1:

#change row names to a list of integers
row.names(mtcars) <- 1:nrow(mtcars)

#view first six row names of mtcars 
head(mtcars)

   mpg cyl disp  hp drat    wt  qsec vs am gear carb
1 21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
2 21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
3 22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
4 21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
5 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
6 18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

You can also use the paste() function to append a word in front of each row name:

#change row names
row.names(mtcars) <- paste("row", 1:nrow(mtcars))

#view first six row names of mtcars 
head(mtcars)

       mpg cyl disp  hp drat    wt  qsec vs am gear carb
row 1 21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
row 2 21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
row 3 22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
row 4 21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
row 5 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
row 6 18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

Note that each row now has the word “row” appended to the front.

Additional Resources

How to Retrieve Row Numbers in R
How to Append Rows to a Data Frame in R
How to Select Random Samples in R

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