1 // ******************************************************************************
2 //
3 // Title: Force Field X.
4 // Description: Force Field X - Software for Molecular Biophysics.
5 // Copyright: Copyright (c) Michael J. Schnieders 2001-2025.
6 //
7 // This file is part of Force Field X.
8 //
9 // Force Field X is free software; you can redistribute it and/or modify it
10 // under the terms of the GNU General Public License version 3 as published by
11 // the Free Software Foundation.
12 //
13 // Force Field X is distributed in the hope that it will be useful, but WITHOUT
14 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
15 // FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
16 // details.
17 //
18 // You should have received a copy of the GNU General Public License along with
19 // Force Field X; if not, write to the Free Software Foundation, Inc., 59 Temple
20 // Place, Suite 330, Boston, MA 02111-1307 USA
21 //
22 // Linking this library statically or dynamically with other modules is making a
23 // combined work based on this library. Thus, the terms and conditions of the
24 // GNU General Public License cover the whole combination.
25 //
26 // As a special exception, the copyright holders of this library give you
27 // permission to link this library with independent modules to produce an
28 // executable, regardless of the license terms of these independent modules, and
29 // to copy and distribute the resulting executable under terms of your choice,
30 // provided that you also meet, for each linked independent module, the terms
31 // and conditions of the license of that module. An independent module is a
32 // module which is not derived from or based on this library. If you modify this
33 // library, you may extend this exception to your version of the library, but
34 // you are not obligated to do so. If you do not wish to do so, delete this
35 // exception statement from your version.
36 //
37 // ******************************************************************************
38 package ffx.numerics.clustering;
39
40 import java.util.Collection;
41
42 /**
43 * Linkage strategy that uses the maximum of pairwise distances between cluster
44 * members (complete-linkage / farthest-neighbor).
45 *
46 * @author Lars Behnke, 2013
47 * @author Michael J. Schnieders
48 * @since 1.0
49 */
50 public class CompleteLinkageStrategy implements LinkageStrategy {
51
52 /**
53 * Computes the complete-linkage distance, i.e., the maximum of provided distances.
54 *
55 * @param distances collection of pairwise distances between cluster members
56 * @return a Distance whose value is the maximum of the inputs
57 */
58 @Override
59 public Distance calculateDistance(Collection<Distance> distances) {
60 double max = Double.NaN;
61
62 for (Distance dist : distances) {
63 if (Double.isNaN(max) || dist.getDistance() > max)
64 max = dist.getDistance();
65 }
66 return new Distance(max);
67 }
68 }