Directed matrix to Undirected matrix

I have directed network matrix which i want to convert to undirected matrix. Suppose i have following directed matrix

G =[0 1 0 1; 0 0 1 1; 1 1 0 1; 0 0 0 0];

which i want to convert to following undirected matrix

 Y = [0 1 1 1; 1 0 1 1; 1 1 0 1; 1 1 1 0];

I run the following code

 for i = 1 : m
    for j = 1 : n
        if G(i,j) == 1  
           G(j,i) = G(i,j);

        else 
            G(i,j)= 0 ;
        end

   end
  end

This code run successfully but instead of overwriting matrix G I want a function which create a new undirected matrix Y from the directed matrix G

Answer 1

[Akira Agata]

How about the following?

Y = G + G' > 0;