def cluster_texts(textdict, eps=0.45, min_samples=3):
"""
cluster the given texts
Input:
textdict: dictionary with {docid: text}
Returns:
doccats: dictionary with {docid: cluster_id}
"""
doc_ids = list(textdict.keys())
# transform texts into length normalized kpca features
ft = FeatureTransform(norm='max', weight=True, renorm='length', norm_num=False)
docfeats = ft.texts2features(textdict)
X, featurenames = features2mat(docfeats, doc_ids)
e_lkpca = KernelPCA(n_components=250, kernel='linear')
X = e_lkpca.fit_transform(X)
xnorm = np.linalg.norm(X, axis=1)
X = X/xnorm.reshape(X.shape[0], 1)
# compute cosine similarity
D = 1. - linear_kernel(X)
# and cluster with dbscan
clst = DBSCAN(eps=eps, metric='precomputed', min_samples=min_samples)
y_pred = clst.fit_predict(D)
return {did: y_pred[i] for i, did in enumerate(doc_ids)}
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