code: public static BasicSymmetricalDistanceMatrix cloneDM(
  			BasicSymmetricalDistanceMatrix distM) {
  
  		int n = distM.getSize();
  		BasicSymmetricalDistanceMatrix cloneDM =
  				new BasicSymmetricalDistanceMatrix(n);
  
  		for (int i = 0; i < n; i++) {
  			cloneDM.setIdentifier(i, distM.getIdentifier(i));
  			for (int j = i + 1; j < n; j++) {
  				cloneDM.setValue(i, j, distM.getValue(i, j));
  			}
  		}
  		return cloneDM;
  	}
docs: Helper function to clone a forester symmetrical DistanceMatrix.
  
  @param distM
  forester symmetrical DistanceMatrix
  @return identical copy of the forester symmetrical DistanceMatrix