Merge 6700791 into 515400d

hdbscan/hdbscan_.py

@@ -989,6 +989,10 @@ def weighted_cluster_centroid(self, cluster_id):
         if not hasattr(self, 'labels_'):
             raise AttributeError('Model has not been fit to data')
 
+        if cluster_id == -1:
+            raise ValueError('Cannot calculate weighted centroid for -1 cluster '
+                             'since it is a noise cluster')
+
         mask = self.labels_ == cluster_id
         cluster_data = self._raw_data[mask]
         cluster_membership_strengths = self.probabilities_[mask]
@@ -1015,6 +1019,10 @@ def weighted_cluster_medoid(self, cluster_id):
         if not hasattr(self, 'labels_'):
             raise AttributeError('Model has not been fit to data')
 
+        if cluster_id == -1:
+            raise ValueError('Cannot calculate weighted centroid for -1 cluster '
+                             'since it is a noise cluster')
+
         mask = self.labels_ == cluster_id
         cluster_data = self._raw_data[mask]
         cluster_membership_strengths = self.probabilities_[mask]

hdbscan/tests/test_hdbscan.py

@@ -602,6 +602,13 @@ def test_hdbscan_centroids_medoids():
         medoid = clusterer.weighted_cluster_medoid(idx)
         assert_array_almost_equal(medoid, center, decimal=1)
 
+
+def test_hdbscan_no_centroid_medoid_for_noise():
+    clusterer = HDBSCAN().fit(X)
+    assert_raises(ValueError, clusterer.weighted_cluster_centroid, -1)
+    assert_raises(ValueError, clusterer.weighted_cluster_medoid, -1)
+
+
 # Disable for now -- need to refactor to meet newer standards
 @SkipTest
 def test_hdbscan_is_sklearn_estimator():