Calculate Trace of a Matrix in R Programming - tr() Function

Last Updated : 15 Jul, 2025
tr() function in R Language is used to calculate the trace of a matrix. Trace of a matrix is the sum of the values on the main diagonal(upper left to lower right) of the matrix.
Syntax: tr(x) Parameters: x: Matrix
Example 1: Python3 1== 
# R program to calculate
# trace of a matrix

# Loading library
library(psych)

# Creating a matrix
A = matrix( 
  c(6, 1, 1, 4, -2, 5, 2, 8, 7),  
  nrow = 3,              
  ncol = 3,              
  byrow = TRUE           
) 

A

# Calling tr() function
cat("Trace of A:\n") 
tr(A)
Output: 
     [, 1] [, 2] [, 3]
[1, ]    6    1    1
[2, ]    4   -2    5
[3, ]    2    8    7
Trace of A:
[1] 11
Example 2: Python3 1== 
# R program to calculate
# trace of a matrix

# Loading library
library(psych)

# Creating a matrix
A = matrix(c(1:9), 3, 3) 

A

# Calling tr() function
cat("Trace of A:\n") 
tr(A)
Output: 
     [, 1] [, 2] [, 3]
[1, ]    1    4    7
[2, ]    2    5    8
[3, ]    3    6    9
Trace of A:
[1] 15
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Article Tags:
R Language
R Matrix-Function

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