@Test
public void calSilhouetteCoefficientTest(){

    Row[] rows0 = new Row[] {
        Row.of(0, "0,0,0"),
        Row.of(0, "0.1,0.1,0.1"),
        Row.of(0, "0.2,0.2,0.2")
    };
    Row[] rows1 = new Row[] {
        Row.of(1, "9 9 9"),
        Row.of(1, "9.1 9.1 9.1"),
        Row.of(1, "9.2 9.2 9.2")
    };
    ClusterMetricsSummary clusterMetricsSummary1 = ClusterEvaluationUtil.getClusterStatistics(Arrays.asList(rows0),
        new EuclideanDistance());
    ClusterMetricsSummary clusterMetricsSummary2 = ClusterEvaluationUtil.getClusterStatistics(Arrays.asList(rows1),
        new EuclideanDistance());
    ClusterMetricsSummary clusterMetricsSummary = clusterMetricsSummary1.merge(clusterMetricsSummary2);
    for(Row row : rows1){
        Assert.assertEquals(0.99, ClusterEvaluationUtil.calSilhouetteCoefficient(row, clusterMetricsSummary).f0, 0.01);
    }
}