data mileages(type=distance);
      title 'Modeclus Analysis of 10 American Cities';
      title2 'Based on Flying Mileages';
   
      input (ATLANTA CHICAGO DENVER HOUSTON LOSANGELES
      MIAMI NEWYORK SANFRAN SEATTLE WASHDC) (5.)
      @53 CITY $15.;
      datalines;
      0                                                ATLANTA
    587    0                                           CHICAGO
   1212  920    0                                      DENVER
    701  940  879    0                                 HOUSTON
   1936 1745  831 1374    0                            LOS ANGELES
    604 1188 1726  968 2339    0                       MIAMI
    748  713 1631 1420 2451 1092    0                  NEW YORK
   2139 1858  949 1645  347 2594 2571    0             SAN FRANCISCO
   2182 1737 1021 1891  959 2734 2408  678    0        SEATTLE
    543  597 1494 1220 2300  923  205 2442 2329    0   WASHINGTON D.C.
   ;

   *-----Fill in Upper Triangle of Distance Matrix---------------;
   proc transpose out=tran;
      copy CITY;
   run;

   data mileages(type=distance);
      merge mileages tran;
      array var ATLANTA--WASHDC;
      array col col1-col10;
      drop col1-col10 _name_;
      do over var;
         var=sum(var,col);
      end;

   *-----Clustering with K-Nearest-Neighbor Density Estimates-----;
   proc modeclus data=mileages all m=1 k=3;
      id CITY;
   run;