How to Extract the Diagonal of a Matrix in R

How to Extract the Diagonal of a Matrix in R ?

To extract the diagonal of a matrix in R, you can use the diag() function. This function retrieves the diagonal elements of a matrix as a vector.

In this example,

First, we create a 2x2 matrix named matrix1 using the matrix() function with a vector of values c(1, 2, 3, 4) and specify the number of rows as 2.
To extract the diagonal elements, we use the diag() function on matrix1 and store the result in a variable called diagonal1.
The diag() function returns a vector containing the diagonal elements of the matrix.
Finally, we use the print() function to display the diagonal elements stored in diagonal1.

matrix1 <- matrix(c(1, 2, 3, 4), nrow = 2)
diagonal1 <- diag(matrix1)
print(diagonal1)

[1] 1 4

In this example,

We first create a 3x3 matrix named matrix2 using the matrix() function with a vector of values c(1, 2, 3, 4, 5, 6, 7, 8, 9) and specify the number of rows as 3.
To extract the diagonal elements, we use the diag() function on matrix2 and store the result in a variable called diagonal2.
The diag() function returns a vector containing the diagonal elements of the matrix.
Finally, we use the print() function to display the diagonal elements stored in diagonal2.

matrix2 <- matrix(c(1, 2, 3, 4, 5, 6, 7, 8, 9), nrow = 3)
diagonal2 <- diag(matrix2)
print(diagonal2)

[1] 1 5 9

In this example,

First, we create a 4x4 matrix named matrix3 using the matrix() function with a vector of values c(10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160) and specify the number of rows as 4.
To extract the diagonal elements, we use the diag() function on matrix3 and store the result in a variable called diagonal3.
The diag() function returns a vector containing the diagonal elements of the matrix.
Finally, we use the print() function to display the diagonal elements stored in diagonal3.

matrix3 <- matrix(c(10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160), nrow = 4)
diagonal3 <- diag(matrix3)
print(diagonal3)

[1]  10  60 110 160

In this tutorial, we learned How to Extract the Diagonal of a Matrix in R language with well detailed examples.