In R, the factor is a data type that categorizes and stores the data as levels. In this tutorial, we will show you how to use the `as.factor()`

function and compare the function and the `factor()`

function. Let’s move on.

**The **`as.factor()`

function in R

`as.factor()`

function in RThe `as.factor()`

function transforms a vector into a factor. In our previous article, we talked about the `factor()`

function to create a factor. Please take a visit if you need clarification about the factor data type.

**Syntax:**

`as.factor(v)`

**Parameters:**

**v:**A vector to convert into a factor object.

**Examples of the **`as.factor()`

function

`as.factor()`

functionThe `as.factor()`

function is simple to understand and use. We will show you the usage of the function in the examples below.

**Use the **`as.factor()`

function with a vector

`as.factor()`

function with a vectorFirst, we will show you an example using the `as.factor()`

function with a vector.

**Code:**

color <- c("red", "orange", "yellow", "orange", "red") fact_object <- as.factor(color) cat("The factor object from a vector is:\n") print(fact_object)

**Result:**

```
The factor object from a vector is:
[1] red orange yellow orange red
Levels: orange red yellow
```

**Use the **`as.factor()`

function with a column

`as.factor()`

function with a columnThe` as.factor()`

function can be applied to a data frame column. Look at the following example for detailed implementation.

**Code:**

shape <- c("square", "oval", "circle", "star", "heart") color <- c("red", "orange", "yellow", "orange", "red") df <- data.frame(shape, color) fact_object <- as.factor(df$color) cat("The factor object from a column is:\n") print(fact_object)

**Result:**

```
The factor object from a column is:
[1] red orange yellow orange red
Levels: orange red yellow
```

**Difference between the **`as.factor()`

and `factor()`

function

`as.factor()`

and `factor()`

function The `as.factor()`

function is considered as a wrapper for factor. It only makes a vector become a factor object, and there is no way to set “labels”, “levels” and “ordered” parameters when using the function. As a result, the function also spends less time than the `factor(`

) function to execute. Look at the following example to compare the runtime of two functions.

**Code:**

color <- c("red", "orange", "yellow", "orange", "red") # Calcualte execution time for the factor() function begin1 <- Sys.time() result1 <- factor(color) finish1 <- Sys.time() time1 <- finish1 - begin1 # Calcualte execution time for the as.factor() function begin2 <- Sys.time() result2 <- as.factor(color) finish2 <- Sys.time() time2 <- finish2 - begin2 if (time1 < time2) { cat("runtime of the factor() function is smaller") } else { cat("runtime of the as.factor() function is smaller") }

**Result:**

`runtime of the as.factor() function is smaller`

## Summary

In summary, the `as.factor()`

function transforms a vector into a factor object. The function is a wrapper of factor and runs faster than the `factor()`

function.

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My name is Robert Collier. I graduated in IT at HUST university. My interest is learning programming languages; my strengths are Python, C, C++, and Machine Learning/Deep Learning/NLP. I will share all the knowledge I have through my articles. Hope you like them.

**Name of the university: **HUST

**Major**: IT

**Programming Languages**: Python, C, C++, Machine Learning/Deep Learning/NLP