R How to Create a List of All Columns Except One (2 Examples)
This page shows how to return a vector of variable names in R programming.
Creation of Example Data
data(iris) # Loading example data frame to R 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 setosa |
data(iris) # Loading example data frame to R 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 setosa
Example 1: Using colnames() Function to Construct Vector that Contains All Variable Names Except One
my_names <- colnames(iris)[colnames(iris) != "Sepal.Width"] # Return colnames my_names # Show vector of colnames # "Sepal.Length" "Petal.Length" "Petal.Width" "Species" |
my_names <- colnames(iris)[colnames(iris) != "Sepal.Width"] # Return colnames my_names # Show vector of colnames # "Sepal.Length" "Petal.Length" "Petal.Width" "Species"
Example 2: Dropping Data Frame Variable Based On Vector of Names
iris_small <- iris[ , my_names] # Removing column head(iris_small) # Show updated iris data # Sepal.Length Petal.Length Petal.Width Species # 1 5.1 1.4 0.2 setosa # 2 4.9 1.4 0.2 setosa # 3 4.7 1.3 0.2 setosa # 4 4.6 1.5 0.2 setosa # 5 5.0 1.4 0.2 setosa # 6 5.4 1.7 0.4 setosa |
iris_small <- iris[ , my_names] # Removing column head(iris_small) # Show updated iris data # Sepal.Length Petal.Length Petal.Width Species # 1 5.1 1.4 0.2 setosa # 2 4.9 1.4 0.2 setosa # 3 4.7 1.3 0.2 setosa # 4 4.6 1.5 0.2 setosa # 5 5.0 1.4 0.2 setosa # 6 5.4 1.7 0.4 setosa