.. note:: :class: sphx-glr-download-link-note Click :ref:`here ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_auto_examples_bicluster_plot_bicluster_newsgroups.py: ================================================================ Biclustering documents with the Spectral Co-clustering algorithm ================================================================ This example demonstrates the Spectral Co-clustering algorithm on the twenty newsgroups dataset. The 'comp.os.ms-windows.misc' category is excluded because it contains many posts containing nothing but data. The TF-IDF vectorized posts form a word frequency matrix, which is then biclustered using Dhillon's Spectral Co-Clustering algorithm. The resulting document-word biclusters indicate subsets words used more often in those subsets documents. For a few of the best biclusters, its most common document categories and its ten most important words get printed. The best biclusters are determined by their normalized cut. The best words are determined by comparing their sums inside and outside the bicluster. For comparison, the documents are also clustered using MiniBatchKMeans. The document clusters derived from the biclusters achieve a better V-measure than clusters found by MiniBatchKMeans. .. rst-class:: sphx-glr-script-out Out: .. code-block:: none Vectorizing... Coclustering... Done in 4.10s. V-measure: 0.4435 MiniBatchKMeans... Done in 6.36s. V-measure: 0.3344 Best biclusters: ---------------- bicluster 0 : 1957 documents, 4363 words categories : 23% talk.politics.guns, 18% talk.politics.misc, 17% sci.med words : gun, guns, geb, banks, gordon, clinton, pitt, cdt, surrender, veal bicluster 1 : 1263 documents, 3551 words categories : 27% soc.religion.christian, 25% talk.politics.mideast, 24% alt.atheism words : god, jesus, christians, sin, objective, kent, belief, christ, faith, moral bicluster 2 : 2212 documents, 2774 words categories : 18% comp.sys.mac.hardware, 17% comp.sys.ibm.pc.hardware, 15% comp.graphics words : voltage, board, dsp, stereo, receiver, packages, shipping, circuit, package, compression bicluster 3 : 1774 documents, 2629 words categories : 27% rec.motorcycles, 23% rec.autos, 13% misc.forsale words : bike, car, dod, engine, motorcycle, ride, honda, bikes, helmet, bmw bicluster 4 : 200 documents, 1167 words categories : 81% talk.politics.mideast, 10% alt.atheism, 8% soc.religion.christian words : turkish, armenia, armenian, armenians, turks, petch, sera, zuma, argic, gvg47 | .. code-block:: python from collections import defaultdict import operator from time import time import numpy as np from sklearn.cluster.bicluster import SpectralCoclustering from sklearn.cluster import MiniBatchKMeans from sklearn.datasets.twenty_newsgroups import fetch_20newsgroups from sklearn.feature_extraction.text import TfidfVectorizer from sklearn.metrics.cluster import v_measure_score print(__doc__) def number_normalizer(tokens): """ Map all numeric tokens to a placeholder. For many applications, tokens that begin with a number are not directly useful, but the fact that such a token exists can be relevant. By applying this form of dimensionality reduction, some methods may perform better. """ return ("#NUMBER" if token[0].isdigit() else token for token in tokens) class NumberNormalizingVectorizer(TfidfVectorizer): def build_tokenizer(self): tokenize = super().build_tokenizer() return lambda doc: list(number_normalizer(tokenize(doc))) # exclude 'comp.os.ms-windows.misc' categories = ['alt.atheism', 'comp.graphics', 'comp.sys.ibm.pc.hardware', 'comp.sys.mac.hardware', 'comp.windows.x', 'misc.forsale', 'rec.autos', 'rec.motorcycles', 'rec.sport.baseball', 'rec.sport.hockey', 'sci.crypt', 'sci.electronics', 'sci.med', 'sci.space', 'soc.religion.christian', 'talk.politics.guns', 'talk.politics.mideast', 'talk.politics.misc', 'talk.religion.misc'] newsgroups = fetch_20newsgroups(categories=categories) y_true = newsgroups.target vectorizer = NumberNormalizingVectorizer(stop_words='english', min_df=5) cocluster = SpectralCoclustering(n_clusters=len(categories), svd_method='arpack', random_state=0) kmeans = MiniBatchKMeans(n_clusters=len(categories), batch_size=20000, random_state=0) print("Vectorizing...") X = vectorizer.fit_transform(newsgroups.data) print("Coclustering...") start_time = time() cocluster.fit(X) y_cocluster = cocluster.row_labels_ print("Done in {:.2f}s. V-measure: {:.4f}".format( time() - start_time, v_measure_score(y_cocluster, y_true))) print("MiniBatchKMeans...") start_time = time() y_kmeans = kmeans.fit_predict(X) print("Done in {:.2f}s. V-measure: {:.4f}".format( time() - start_time, v_measure_score(y_kmeans, y_true))) feature_names = vectorizer.get_feature_names() document_names = list(newsgroups.target_names[i] for i in newsgroups.target) def bicluster_ncut(i): rows, cols = cocluster.get_indices(i) if not (np.any(rows) and np.any(cols)): import sys return sys.float_info.max row_complement = np.nonzero(np.logical_not(cocluster.rows_[i]))[0] col_complement = np.nonzero(np.logical_not(cocluster.columns_[i]))[0] # Note: the following is identical to X[rows[:, np.newaxis], # cols].sum() but much faster in scipy <= 0.16 weight = X[rows][:, cols].sum() cut = (X[row_complement][:, cols].sum() + X[rows][:, col_complement].sum()) return cut / weight def most_common(d): """Items of a defaultdict(int) with the highest values. Like Counter.most_common in Python >=2.7. """ return sorted(d.items(), key=operator.itemgetter(1), reverse=True) bicluster_ncuts = list(bicluster_ncut(i) for i in range(len(newsgroups.target_names))) best_idx = np.argsort(bicluster_ncuts)[:5] print() print("Best biclusters:") print("----------------") for idx, cluster in enumerate(best_idx): n_rows, n_cols = cocluster.get_shape(cluster) cluster_docs, cluster_words = cocluster.get_indices(cluster) if not len(cluster_docs) or not len(cluster_words): continue # categories counter = defaultdict(int) for i in cluster_docs: counter[document_names[i]] += 1 cat_string = ", ".join("{:.0f}% {}".format(float(c) / n_rows * 100, name) for name, c in most_common(counter)[:3]) # words out_of_cluster_docs = cocluster.row_labels_ != cluster out_of_cluster_docs = np.where(out_of_cluster_docs)[0] word_col = X[:, cluster_words] word_scores = np.array(word_col[cluster_docs, :].sum(axis=0) - word_col[out_of_cluster_docs, :].sum(axis=0)) word_scores = word_scores.ravel() important_words = list(feature_names[cluster_words[i]] for i in word_scores.argsort()[:-11:-1]) print("bicluster {} : {} documents, {} words".format( idx, n_rows, n_cols)) print("categories : {}".format(cat_string)) print("words : {}\n".format(', '.join(important_words))) **Total running time of the script:** ( 0 minutes 13.291 seconds) .. _sphx_glr_download_auto_examples_bicluster_plot_bicluster_newsgroups.py: .. only :: html .. container:: sphx-glr-footer :class: sphx-glr-footer-example .. container:: sphx-glr-download :download:`Download Python source code: plot_bicluster_newsgroups.py ` .. container:: sphx-glr-download :download:`Download Jupyter notebook: plot_bicluster_newsgroups.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_