Unique Values in Data Frame Variables in R (2 Examples)
In this R tutorial you’ll learn how to get the unique value (counts) in all data frame columns.
Creation of Example Data
data(iris) # Example data 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) # Example data 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: Count Unique Values by Data Frame Column
rapply(iris, function(x) length(unique(x))) # Counting uniques # Sepal.Length Sepal.Width Petal.Length Petal.Width Species # 35 23 43 22 3 |
rapply(iris, function(x) length(unique(x))) # Counting uniques # Sepal.Length Sepal.Width Petal.Length Petal.Width Species # 35 23 43 22 3
Example 2: Display Unique Values by Data Frame Column
lapply(iris, unique) # Display unique values # $Sepal.Length # [1] 5.1 4.9 4.7 4.6 5.0 5.4 4.4 4.8 4.3 5.8 5.7 5.2 5.5 4.5 5.3 7.0 6.4 6.9 6.5 6.3 6.6 5.9 6.0 6.1 5.6 6.7 6.2 6.8 7.1 7.6 7.3 7.2 7.7 7.4 7.9 # # $Sepal.Width # [1] 3.5 3.0 3.2 3.1 3.6 3.9 3.4 2.9 3.7 4.0 4.4 3.8 3.3 4.1 4.2 2.3 2.8 2.4 2.7 2.0 2.2 2.5 2.6 # # $Petal.Length # [1] 1.4 1.3 1.5 1.7 1.6 1.1 1.2 1.0 1.9 4.7 4.5 4.9 4.0 4.6 3.3 3.9 3.5 4.2 3.6 4.4 4.1 4.8 4.3 5.0 3.8 3.7 5.1 3.0 6.0 5.9 5.6 5.8 6.6 6.3 6.1 5.3 5.5 6.7 6.9 5.7 6.4 5.4 5.2 # # $Petal.Width # [1] 0.2 0.4 0.3 0.1 0.5 0.6 1.4 1.5 1.3 1.6 1.0 1.1 1.8 1.2 1.7 2.5 1.9 2.1 2.2 2.0 2.4 2.3 # # $Species # [1] setosa versicolor virginica # Levels: setosa versicolor virginica # |
lapply(iris, unique) # Display unique values # $Sepal.Length # [1] 5.1 4.9 4.7 4.6 5.0 5.4 4.4 4.8 4.3 5.8 5.7 5.2 5.5 4.5 5.3 7.0 6.4 6.9 6.5 6.3 6.6 5.9 6.0 6.1 5.6 6.7 6.2 6.8 7.1 7.6 7.3 7.2 7.7 7.4 7.9 # # $Sepal.Width # [1] 3.5 3.0 3.2 3.1 3.6 3.9 3.4 2.9 3.7 4.0 4.4 3.8 3.3 4.1 4.2 2.3 2.8 2.4 2.7 2.0 2.2 2.5 2.6 # # $Petal.Length # [1] 1.4 1.3 1.5 1.7 1.6 1.1 1.2 1.0 1.9 4.7 4.5 4.9 4.0 4.6 3.3 3.9 3.5 4.2 3.6 4.4 4.1 4.8 4.3 5.0 3.8 3.7 5.1 3.0 6.0 5.9 5.6 5.8 6.6 6.3 6.1 5.3 5.5 6.7 6.9 5.7 6.4 5.4 5.2 # # $Petal.Width # [1] 0.2 0.4 0.3 0.1 0.5 0.6 1.4 1.5 1.3 1.6 1.0 1.1 1.8 1.2 1.7 2.5 1.9 2.1 2.2 2.0 2.4 2.3 # # $Species # [1] setosa versicolor virginica # Levels: setosa versicolor virginica #
Related Tutorials
Here, you may find some additional resources on topics such as matrices, counting, and character strings.