# Ruby program for tr() method in Matrix
   
# Include matrix 
require "matrix"
   
# Initialize a matrix 
mat1 = Matrix[[3, 12], [2, 8]]  
   
# Prints the trace
puts  mat1.tr()

11

# Ruby program for tr() method in Matrix
   
# Include matrix 
require "matrix"
   
# Initialize a matrix 
mat1 = Matrix[[1, 0, 6], [6, 1, 7], [1, 2, 19]]   
   
# Prints the trace
puts  mat1.tr()

21