How to Rename a Single Column in a Data.frame?

To rename a single column in a data.frame in R, you can use the colnames() function or the dplyr package. Below are the methods to rename a single column:

Method 1: Using colnames() Function

# Sample data frame
df <- data.frame(A = 1:3, B = 4:6)

# Rename column "A" to "X"
colnames(df)[colnames(df) == "A"] <- "X"

# View the updated data frame
print(df)

Explanation:

• colnames(df) retrieves the column names of the data frame.
• The condition colnames(df) == "A" finds the index of the column you want to rename.
• colnames(df)[colnames(df) == "A"] <- "X" assigns the new name (“X”) to the identified column.

Method 2: Using dplyr Package (rename() Function)

If you’re using the dplyr package, you can use the rename() function, which is more intuitive:

# Load dplyr package
library(dplyr)

# Sample data frame
df <- data.frame(A = 1:3, B = 4:6)

# Rename column "A" to "X"
df <- df %>%
  rename(X = A)

# View the updated data frame
print(df)

Explanation:

• The rename() function from dplyr is used where the new column name (X) is specified before the old column name (A).

Method 3: Using Base R Assignment

Another quick way is to directly access the column by index:

# Sample data frame
df <- data.frame(A = 1:3, B = 4:6)

# Rename column "A" to "X"
names(df)[1] <- "X"

# View the updated data frame
print(df)

Explanation:

• names(df) returns the column names as a vector, and you can modify it by referring to the column index (e.g., 1 for the first column).

Summary

• Use colnames() if you’re working with base R.
• Use dplyr::rename() for a more readable syntax and when working with the dplyr package.
• You can also use names() for quick access to column names.