title: How to produce random symmetric matrix given the number of vertices?
body: <p>Is there a simple way to produce a random matrix of 0's and 1's, that is symmetric across the diagonal (with only zeros in the diagonal), given the number of vertices? </p>
  
  <p><strong>Example:</strong> </p>
  
  <pre><code>somefunction(3) =  [ 0 1 1; 
                       1 0 0; 
                       1 0 0]; 
  
  somefunction(4) = [ 0 1 1 1; 
                      1 0 0 1; 
                      1 0 0 1; 
                      1 1 1 0];
  </code></pre>