def test_cluster_center_resize(self):
center = numpy.array([0, 0, 1, 1, 0, 1])
terms = ['test0', 'test1', 'test2', 'test3', 'test4', 'test5']
cluster = OnlineCluster(center, 1, 1, "test", terms)
#'Test a longer term vector
new_terms_longer_list = [
'test0', 'test1', 'test2', 'test3', 'test4', 'test5', 'test6',
'test7'
]
cluster.resize(new_terms_longer_list)
expected_center = numpy.array([0, 0, 1, 1, 0, 1, 0,
0]) #2 zeroes in the end
self.assertTrue(numpy.sum(expected_center - cluster.center) == 0)
self.assertEquals(new_terms_longer_list, cluster.term_vector)
#'Test a smaller term vector
new_terms_smaller_list = ['test0', 'test1', 'test2', 'test3']
cluster.resize(new_terms_smaller_list)
expected_center = numpy.array([0, 0, 1, 1])
self.assertTrue(numpy.sum(expected_center - cluster.center) == 0)
self.assertEquals(new_terms_smaller_list, cluster.term_vector)
#Test a longer term vector and shuffled
new_terms_longer_listand_shuffled = [
'test7', 'test0', 'test5', 'test2', 'test1', 'test3', 'test4',
'test6'
]
cluster.resize(new_terms_longer_listand_shuffled)
expected_center = numpy.array([0, 0, 0, 1, 0, 1, 0, 0])
self.assertTrue(numpy.sum(expected_center - cluster.center) == 0)
self.assertEquals(new_terms_longer_listand_shuffled,
cluster.term_vector)
def plot_scatter(self):
'''
Overrides the parent class method. Plots all the data points in 2D.
'''
#Create a clusterer document list to get the index of a doc (horrible hack I know)
clusterer_document_list = [key for key in self.document_dict.keys()]
corpus = nltk.TextCollection(
[document.tokens for document in self.document_dict.values()])
all_terms_vector = list(set(corpus))
table = construct_orange_table(all_terms_vector)
meta_col_name = "cluster_id"
table = add_metas_to_table(table, meta_col_name=meta_col_name)
instances = []
for cluster in self.clusters:
for doc_id, doc_content in cluster.document_dict.iteritems():
index = clusterer_document_list.index(doc_id)
#We use index = 1 to force the function to construct the vector according to all the documents in the collection
self.construct_term_doc_matrix(index, doc_content)
oc = OnlineCluster(self.td_matrix, 1, doc_id, doc_content,
self.attributes)
oc.resize(all_terms_vector)
inst = Orange.data.Instance(table.domain, list(oc.center))
inst[meta_col_name] = str(cluster.id)
instances.insert(index, inst)
#we have a table with the clusters ids as metas.
table.extend(instances)
from visualizations.mds import MDS
mds = MDS(table)
classes_list = []
for c in self.clusters:
classes_list.append(c.id)
mds.plot(classes_list=classes_list, class_col_name="cluster_id")
def cluster(self, document):
'''
Performs clustering for a new document. It takes as input
a document object from the db and finds the closer cluster for it.
'''
doc_index = self.add_document(document)
doc_id = str(document.id)
doc_content = document.content
self.construct_term_doc_matrix(index=doc_index, document=doc_content)
print 'N', len(self.clusters)
print 'clustering', doc_index
if doc_index > 0: #ignore the first document
#e = doc_index
e = self.td_matrix
newc = OnlineCluster(a=e,
cluster_id=self.cluster_id_counter,
doc_id=doc_id,
doc_content=doc_content,
term_vector=self.attributes)
#If the new term vector is larger then change all the cluster centers
#However, if the new term vector is smaller then pad the new cluster's center
if len(self.clusters) > 0:
if len(newc.term_vector) > len(self.clusters[0].term_vector):
self.resize()
else:
newc.resize(self.clusters[0].term_vector)
e = newc.center
if len(self.clusters) > 0:
# Compare the new document to each existing cluster
c = [(i, kernel_dist(x.center, e))
for i, x in enumerate(self.clusters)]
closest_cluster = min(c, key=operator.itemgetter(1))
if closest_cluster[1] < 1.0:
closest = self.clusters[closest_cluster[0]]
closest.add(e, doc_id, doc_content)
# invalidate dist-cache for this cluster
self.updatedist(closest)
else:
# make a new cluster for this point
self.clusters.append(newc)
self.updatedist(newc)
if len(self.clusters) >= self.N and len(self.clusters) > 1:
# merge closest two clusters. It doesn't matter which ones, Only the closest
m = heapq.heappop(self.dist)
m.x.merge(m.y)
self.clusters.remove(m.y)
self.removedist(m.y)
self.updatedist(m.x)
self.cluster_id_counter += 1
else:
newc = OnlineCluster(a=self.td_matrix,
cluster_id=self.cluster_id_counter,
doc_id=doc_id,
doc_content=doc_content,
term_vector=self.attributes)
self.clusters.append(newc)
self.updatedist(newc)