title: I need to export a distance matrix in its triangular form to a .txt or a .csv file
body: <p>So far I've tried all what I have found in internet.
  I have a distance matrix (dist class) and all the elements I've learned to "coerce" the matrix have not been effective. 
  I want to keep the triangular form.</p>
  
  <p>Does any one already know how to export a dist matrix?
  f</p>