associated with that variable; to release the memory, you
   must run the command 'clear functions'.  Further, DISTS may be
   unexpectedly modified by later calls to PAIRDIST.  For example,

       A = PAIRDIST(X1,Y1);         % Look at the value of A(1,2)
       B = PAIRDIST(X2,Y2,'reuse'); % The value of A(1,2) will change
                                    % here even though A was not assigned

   If this behavior is undesirable, make a copy of the returned distance
   matrix before calling PAIRDIST ag