Construct a Diagonal Matrix in R Programming – diag() Function

diag() function in R Language is used to construct a diagonal matrix.

Syntax: diag(x, nrow, ncol)
Parameters:
x: value present as the diagonal elements. 
nrow, ncol: number of rows and columns in which elements are represented. 

Example 1:

Python3

# R program to illustrate
# diag function

# Calling the diag() function with
# some number which will act as
# rows as well as columns number
diag(3)
diag(5)

Output:

     [, 1] [, 2] [, 3]
[1, ]    1    0    0
[2, ]    0    1    0
[3, ]    0    0    1

     [, 1] [, 2] [, 3] [, 4] [, 5]
[1, ]    1    0    0    0    0
[2, ]    0    1    0    0    0
[3, ]    0    0    1    0    0
[4, ]    0    0    0    1    0
[5, ]    0    0    0    0    1

Example 2:

Python3

# R program to illustrate
# diag function

# Calling the diag() function
diag(5, 2, 3)
diag(10, 3, 3)

Output:

     [, 1] [, 2] [, 3]
[1, ]    5    0    0
[2, ]    0    5    0

     [, 1] [, 2] [, 3]
[1, ]   10    0    0
[2, ]    0   10    0
[3, ]    0    0   10