How to Compute a Correlation Matrix in R
In this R tutorial you’ll learn how to create a matrix containing correlation coefficients.
Example Data in R
data(iris) # Load iris data head(iris) # Head of iris data # Sepal.Length Sepal.Width Petal.Length Petal.Width Species # 1 5.1 3.5 1.4 0.2 setosa # 2 4.9 3.0 1.4 0.2 setosa # 3 4.7 3.2 1.3 0.2 setosa # 4 4.6 3.1 1.5 0.2 setosa # 5 5.0 3.6 1.4 0.2 setosa # 6 5.4 3.9 1.7 0.4 setosa |
data(iris) # Load iris data head(iris) # Head of iris data # Sepal.Length Sepal.Width Petal.Length Petal.Width Species # 1 5.1 3.5 1.4 0.2 setosa # 2 4.9 3.0 1.4 0.2 setosa # 3 4.7 3.2 1.3 0.2 setosa # 4 4.6 3.1 1.5 0.2 setosa # 5 5.0 3.6 1.4 0.2 setosa # 6 5.4 3.9 1.7 0.4 setosa
Example: Correlation Matrix of Iris Data Set
cor(iris[ , 1:4]) # Get correlation matrix of iris # Sepal.Length Sepal.Width Petal.Length Petal.Width # Sepal.Length 1.0000000 -0.1175698 0.8717538 0.8179411 # Sepal.Width -0.1175698 1.0000000 -0.4284401 -0.3661259 # Petal.Length 0.8717538 -0.4284401 1.0000000 0.9628654 # Petal.Width 0.8179411 -0.3661259 0.9628654 1.0000000 |
cor(iris[ , 1:4]) # Get correlation matrix of iris # Sepal.Length Sepal.Width Petal.Length Petal.Width # Sepal.Length 1.0000000 -0.1175698 0.8717538 0.8179411 # Sepal.Width -0.1175698 1.0000000 -0.4284401 -0.3661259 # Petal.Length 0.8717538 -0.4284401 1.0000000 0.9628654 # Petal.Width 0.8179411 -0.3661259 0.9628654 1.0000000