unclass Function in R (2 Examples)
In this R tutorial you’ll learn how to apply the unclass() function.
The post is structured as follows:
Let’s just jump right in…
Creating Example Data
We’ll use the following data as a basis for this tutorial:
my_fac <- factor(c("A", "B", "A", "A", "C")) # Create example factor my_fac # Print example factor # [1] A B A A C # Levels: A B C
As you can see based on the previously shown output of the RStudio console, our example data is a factor vector containing the three different factor levels A, B, and C.
Example 1: Convert Factor to Integer Using unclass() Function
The following R programming syntax shows how to use the unclass function to transform a factor vector to an integer.
Consider the R code below:
my_fac_new1 <- unclass(my_fac) # Convert factor to integer my_fac_new1 # Print output # [1] 1 2 1 1 3 # attr(,"levels") # [1] "A" "B" "C"
As you can see, we have created a new data object called my_fac_new1, which contains integer values that correspond to the different levels of our input factor.
Let’s check the data class of this new data object:
class(my_fac_new1) # Check class of updated data # [1] "integer"
As you can see, our new data object has the integer class.
Example 2: Change Group Names of Factor Using unclass() Function
This example shows how to use the unclass command to change the groups/categories of a factor object.
For this, we first have to create a new vector that contains the new group names:
new_names <- c("gr1", "gr2", "gr3") # Specify new group names new_names # Print new group names # [1] "gr1" "gr2" "gr3"
Next, we can use the unclass function to switch the categories in our factor to the new names:
my_fac_new2 <- new_names[unclass(my_fac)] # Change factor levels my_fac_new2 # Print new data # [1] "gr1" "gr2" "gr1" "gr1" "gr3"
The factor level A was renamed to “gr1”, B was renamed to “gr2”, and C was renamed to “gr3”.
Note that the previously created data object my_fac_new2 has the character class. You might convert this vector back to the factor class, though.
Video, Further Resources & Summary
Do you need further explanations on the R programming code of this article? Then you might have a look at the following video on my YouTube channel. In the video, I’m explaining the topics of this tutorial.
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In addition, you may have a look at the other tutorials on this website:
- https://statisticsglobe.com/change-classes-data-frame-columns-automatically-r
- Determine Classes of All Data Frame Columns
- Useful Commands in R
- R Programming Language
To summarize: You have learned in this tutorial how to use the unclass() function in R programming. In case you have any further questions, let me know in the comments section below.
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