How to Compute z-scores in R Programming (Example Code)
In this article, I’ll explain how to calculate z-scores in the R programming language.
Creation of Example Data
data(iris) # Load iris flower data iris_num <- iris[ , 1:4] # Remove non-numeric columns head(iris_num) # Head of numeric iris data # Sepal.Length Sepal.Width Petal.Length Petal.Width # 1 5.1 3.5 1.4 0.2 # 2 4.9 3.0 1.4 0.2 # 3 4.7 3.2 1.3 0.2 # 4 4.6 3.1 1.5 0.2 # 5 5.0 3.6 1.4 0.2 # 6 5.4 3.9 1.7 0.4 |
data(iris) # Load iris flower data iris_num <- iris[ , 1:4] # Remove non-numeric columns head(iris_num) # Head of numeric iris data # Sepal.Length Sepal.Width Petal.Length Petal.Width # 1 5.1 3.5 1.4 0.2 # 2 4.9 3.0 1.4 0.2 # 3 4.7 3.2 1.3 0.2 # 4 4.6 3.1 1.5 0.2 # 5 5.0 3.6 1.4 0.2 # 6 5.4 3.9 1.7 0.4
Example: Standardize Variables of Data Frame Using scale() Function
iris_num_scaled <- scale(iris_num) # Scaling data head(iris_num_scaled) # Head of scaled data # Sepal.Length Sepal.Width Petal.Length Petal.Width # [1,] -0.8976739 1.01560199 -1.335752 -1.311052 # [2,] -1.1392005 -0.13153881 -1.335752 -1.311052 # [3,] -1.3807271 0.32731751 -1.392399 -1.311052 # [4,] -1.5014904 0.09788935 -1.279104 -1.311052 # [5,] -1.0184372 1.24503015 -1.335752 -1.311052 # [6,] -0.5353840 1.93331463 -1.165809 -1.048667 |
iris_num_scaled <- scale(iris_num) # Scaling data head(iris_num_scaled) # Head of scaled data # Sepal.Length Sepal.Width Petal.Length Petal.Width # [1,] -0.8976739 1.01560199 -1.335752 -1.311052 # [2,] -1.1392005 -0.13153881 -1.335752 -1.311052 # [3,] -1.3807271 0.32731751 -1.392399 -1.311052 # [4,] -1.5014904 0.09788935 -1.279104 -1.311052 # [5,] -1.0184372 1.24503015 -1.335752 -1.311052 # [6,] -0.5353840 1.93331463 -1.165809 -1.048667