[MATH-1374] KMeansPlusPlusClusterer unable to converge having repeatable points in input dataset

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: 4.X
• Assignee: Artem Barger
• Reporter: Artem Barger
• Created: 02/Jun/16 10:13
• Updated: 07/Jun/21 03:03

Description

If the input list size of Clusterable is greater than parameter k while has less unique points than k, the algorithm will fail to converge, tested w/ different EmptyClusterStrategy options, here is the example of default one:

   @Test
    public void testNumberOfRequestedClustersSameAsInputSize() {

        final RandomVectorGenerator rng = new UncorrelatedRandomVectorGenerator(10,
                new GaussianRandomGenerator(RandomSource.create(RandomSource.MT)));

        List<DoublePoint> points = new ArrayList<>();

        for (int i = 0; i < 10; i++) {
            final DoublePoint point = new DoublePoint(rng.nextVector());
            for (int j = 0; j < 3; j++) {
                points.add(point);
            }
        }

        final KMeansPlusPlusClusterer<DoublePoint> clusterer = new KMeansPlusPlusClusterer<>(12);
        clusterer.cluster(points);
    }

Issue Links

• is related to: MATH-1515 Enhance clustering API
• links to: GitHub Pull Request #37