How to Rename Levels of a Factor in R - Step by Step Examples

How to Rename Levels of a Factor in R ?

Answer

To rename levels of a factor in R, you can use the levels() function to access and modify the levels of a factor. This is useful when you need to change the names of levels to more meaningful or standardized labels.

✐ Examples

1 Renaming Levels of a Factor Representing Animal Types

In this example,

We start by creating a character vector named animals which contains the values 'dog', 'cat', and 'bird'. This vector represents different types of animals.
Next, we use the factor() function to convert the animals vector into a factor. We assign the result to a variable named animals_factor. The factor() function automatically identifies the unique levels of the vector, which in this case are 'dog', 'cat', and 'bird'.
We then use the levels() function to rename the levels of the animals_factor. We assign a new vector of level names c('Canine', 'Feline', 'Avian') to the levels() function applied to animals_factor. This changes the level names from 'dog', 'cat', and 'bird' to 'Canine', 'Feline', and 'Avian' respectively.
We print the modified animals_factor to the console to see the renamed levels. This allows us to verify that the levels have been correctly renamed.

R Program

animals <- c('dog', 'cat', 'bird')
animals_factor <- factor(animals)
levels(animals_factor) <- c('Canine', 'Feline', 'Avian')
print(animals_factor)

Output

[1] Canine Feline Avian 
Levels: Canine Feline Avian

2 Renaming Levels of a Factor Representing Seasons

In this example,

We start by creating a character vector named seasons which contains the values 'spring', 'summer', 'fall', and 'winter'. This vector represents different seasons of the year.
Next, we use the factor() function to convert the seasons vector into a factor. We assign the result to a variable named seasons_factor. The factor() function automatically identifies the unique levels of the vector, which in this case are 'spring', 'summer', 'fall', and 'winter'.
We then use the levels() function to rename the levels of the seasons_factor. We assign a new vector of level names c('Springtime', 'Summertime', 'Autumn', 'Wintertime') to the levels() function applied to seasons_factor. This changes the level names from 'spring', 'summer', 'fall', and 'winter' to 'Springtime', 'Summertime', 'Autumn', and 'Wintertime' respectively.
We print the modified seasons_factor to the console to see the renamed levels. This allows us to verify that the levels have been correctly renamed.

R Program

seasons <- c('spring', 'summer', 'fall', 'winter')
seasons_factor <- factor(seasons)
levels(seasons_factor) <- c('Springtime', 'Summertime', 'Autumn', 'Wintertime')
print(seasons_factor)

Output

[1] Springtime Summertime Autumn      Wintertime 
Levels: Springtime Summertime Autumn Wintertime

3 Renaming Levels of a Factor Representing Survey Responses

In this example,

We start by creating a character vector named responses which contains the values 'yes', 'no', and 'maybe'. This vector represents different types of survey responses.
Next, we use the factor() function to convert the responses vector into a factor. We assign the result to a variable named responses_factor. The factor() function automatically identifies the unique levels of the vector, which in this case are 'yes', 'no', and 'maybe'.
We then use the levels() function to rename the levels of the responses_factor. We assign a new vector of level names c('Agree', 'Disagree', 'Neutral') to the levels() function applied to responses_factor. This changes the level names from 'yes', 'no', and 'maybe' to 'Agree', 'Disagree', and 'Neutral' respectively.
We print the modified responses_factor to the console to see the renamed levels. This allows us to verify that the levels have been correctly renamed.

R Program

responses <- c('yes', 'no', 'maybe')
responses_factor <- factor(responses)
levels(responses_factor) <- c('Agree', 'Disagree', 'Neutral')
print(responses_factor)

Output

[1] Agree    Disagree Neutral 
Levels: Agree Disagree Neutral

Summary

In this tutorial, we learned How to Rename Levels of a Factor in R language with well detailed examples.

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