1 Goal


The goal of this tutorial is to learn how to change the name of the levels of a factor.


2 Rename levels


# First of all we load the data
# For this tutorial we are going to use the iris plant dataset
data(iris)
str(iris)
## 'data.frame':    150 obs. of  5 variables:
##  $ Sepal.Length: num  5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 ...
##  $ Sepal.Width : num  3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1 ...
##  $ Petal.Length: num  1.4 1.4 1.3 1.5 1.4 1.7 1.4 1.5 1.4 1.5 ...
##  $ Petal.Width : num  0.2 0.2 0.2 0.2 0.2 0.4 0.3 0.2 0.2 0.1 ...
##  $ Species     : Factor w/ 3 levels "setosa","versicolor",..: 1 1 1 1 1 1 1 1 1 1 ...
# We can obtain the levels of the plants 
levels(iris$Species)
## [1] "setosa"     "versicolor" "virginica"
# We can now rename the levels 
levels(iris$Species) <- c("Plant 1", "Plant 2", "Plant 3")

# And check the new levels
levels(iris$Species)
## [1] "Plant 1" "Plant 2" "Plant 3"

3 Conclusion


In this tutorial we have learnt how to rename levels of a factor.