Error Message in R: Function must only be used inside dplyr verbs (2 Examples)
In this R post you’ll learn how to handle the error message “must only be used inside dplyr verbs”.
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: Replicating the Error Message: `n()` must only be used inside dplyr verbs.
install.packages("dplyr") # Install & load dplyr library("dplyr") |
install.packages("dplyr") # Install & load dplyr library("dplyr")
install.packages("plyr") # Install plyr package library("plyr") # Load plyr package |
install.packages("plyr") # Install plyr package library("plyr") # Load plyr package
iris %>% # Code leads to error group_by(Species) %>% summarize(freq = n()) # Error: `n()` must only be used inside dplyr verbs. |
iris %>% # Code leads to error group_by(Species) %>% summarize(freq = n()) # Error: `n()` must only be used inside dplyr verbs.
Example 2: Solving the Error Message: `n()` must only be used inside dplyr verbs.
iris %>% # Code leads to error group_by(Species) %>% dplyr::summarize(freq = n()) # # A tibble: 3 x 2 # Species freq # <fct> <int> # 1 setosa 50 # 2 versicolor 50 # 3 virginica 50 |
iris %>% # Code leads to error group_by(Species) %>% dplyr::summarize(freq = n()) # # A tibble: 3 x 2 # Species freq # <fct> <int> # 1 setosa 50 # 2 versicolor 50 # 3 virginica 50
Further Resources
In addition, you could have a look at the related R programming tutorials of my homepage.