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Dropping columns from a data frame in R is a simple process. Through the use of the select() and the – operator, you can easily drop multiple columns from a data frame in R. This can be done by passing a vector of column names to the select() function, or by using the – operator to remove the columns from the data frame. Additionally, the select() and drop_na() functions can be used to remove columns with blank or NA values. To further illustrate this, examples of dropping columns from a data frame in R are provided.
The easiest way to drop columns from a data frame in R is to use the subset() function, which uses the following basic syntax:
#remove columns var1 and var3 new_df <- subset(df, select = -c(var1, var3))
The following examples show how to use this function in practice with the following data frame:
#create data frame df <- data.frame(var1=c(1, 3, 3, 4, 5), var2=c(7, 7, 8, 3, 2), var3=c(3, 3, 6, 10, 12), var4=c(14, 16, 22, 19, 18)) #view data frame df var1 var2 var3 var4 1 1 7 3 14 2 3 7 3 16 3 3 8 6 22 4 4 3 10 19 5 5 2 12 18
Example 1: Drop Columns by Name
The following code shows how to drop columns from the data frame by name:
#remove columns var1 and var3 new_df <- subset(df, select = -c(var1, var3)) #view updated data frame new_df var2 var4 1 7 14 2 7 16 3 8 22 4 3 19 5 2 18
Example 2: Drop Columns by Index
The following code shows how to drop columns from the data frame by index:
#remove first and fourth columns new_df <- subset(df, select = -c(1, 4)) #view updated data frame new_df var2 var3 1 7 3 2 7 3 3 8 6 4 3 10 5 2 12
Example 3: Drop Columns in List
The following code shows how to drop columns from the data frame that belong to a certain list:
#define list of columns to remove remove_cols <- c('var1', 'var4') #remove columns in list new_df = subset(df, select = !(names(df) %in% remove_cols)) #view updated data frame new_df var2 var3 1 7 3 2 7 3 3 8 6 4 3 10 5 2 12
Example 4: Drop Columns in Range
The following code shows how to drop columns from the data frame in a certain range:
#remove columns in range of 1 to 3 new_df = subset(df, select = -c(1:3)) #view updated data frame new_df var4 1 14 2 16 3 22 4 19 5 18