Standardize Data Frame Columns in R (2 Examples) | scale Function
In this tutorial, I’ll illustrate how to scale a data frame in R programming.
Table of contents:
Let’s dig in:
Example Data
First, we have to create some example data:
set.seed(936757) # Create example data data <- data.frame(x1 = runif(100), x2 = runif(100)) head(data) # Head of example data # x1 x2 # 1 0.1455930 0.4151339 # 2 0.1524390 0.8134210 # 3 0.2395215 0.7935963 # 4 0.7515754 0.5283296 # 5 0.7779833 0.4289751 # 6 0.6350550 0.8990219
Have a look at the previous output of the RStudio console. It shows that our example data consists of two numeric columns x1 and x2.
Example 1: Scaling Data Frame Using scale() Function
The following R syntax shows how to standardize our example data using the scale function in R.
As you can see in the following R code, we simply have to insert the name of our data frame (i.e. data) into the scale function:
data_scale1 <- scale(data) # Apply scale function head(data_scale1) # Head of scaled data # x1 x2 # [1,] -1.2764344 -0.433002745 # [2,] -1.2523528 1.058137478 # [3,] -0.9460274 0.983916110 # [4,] 0.8551967 -0.009211208 # [5,] 0.9480902 -0.381182671 # [6,] 0.4453192 1.378617326
The previous output of the RStudio console shows the first six rows of our standardized data.
Example 2: Scaling Data Frame Using dplyr Package
Alternatively to the scale function we can also use functions of the dplyr add-on package. First, we need to install and load the dplyr package to RStudio:
install.packages("dplyr") # Install & load dplyr package library("dplyr")
Now, we can standardize our data frame using the dplyr package as shown below:
data_scale2 <- data %>% # Applying functions of dplyr mutate_at(c("x1", "x2"), ~(scale(.) %>% as.vector)) head(data_scale2) # Head of scaled data # x1 x2 # 1 -1.2764344 -0.433002745 # 2 -1.2523528 1.058137478 # 3 -0.9460274 0.983916110 # 4 0.8551967 -0.009211208 # 5 0.9480902 -0.381182671 # 6 0.4453192 1.378617326
As you can see, the output is exactly the same as in Example 1.
Video & Further Resources
Have a look at the following video of my YouTube channel. I’m explaining the R programming code of this page in the video instruction:
The YouTube video will be added soon.
In addition, you might read the other tutorials of this website:
This article explained how to standardize data frame variables in the R programming language. Please let me know in the comments section, in case you have any further questions.
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