.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "auto_examples/semi_supervised/plot_semi_supervised_newsgroups.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code. or to run this example in your browser via Binder .. rst-class:: sphx-glr-example-title .. _sphx_glr_auto_examples_semi_supervised_plot_semi_supervised_newsgroups.py: ================================================ Semi-supervised Classification on a Text Dataset ================================================ In this example, semi-supervised classifiers are trained on the 20 newsgroups dataset (which will be automatically downloaded). You can adjust the number of categories by giving their names to the dataset loader or setting them to `None` to get all 20 of them. .. GENERATED FROM PYTHON SOURCE LINES 13-112 .. rst-class:: sphx-glr-script-out .. code-block:: none 2823 documents 5 categories Supervised SGDClassifier on 100% of the data: Number of training samples: 2117 Unlabeled samples in training set: 0 Micro-averaged F1 score on test set: 0.885 ---------- Supervised SGDClassifier on 20% of the training data: Number of training samples: 411 Unlabeled samples in training set: 0 Micro-averaged F1 score on test set: 0.773 ---------- SelfTrainingClassifier on 20% of the training data (rest is unlabeled): Number of training samples: 2117 Unlabeled samples in training set: 1706 End of iteration 1, added 1076 new labels. End of iteration 2, added 222 new labels. End of iteration 3, added 56 new labels. End of iteration 4, added 22 new labels. End of iteration 5, added 10 new labels. End of iteration 6, added 8 new labels. End of iteration 7, added 9 new labels. End of iteration 8, added 6 new labels. End of iteration 9, added 5 new labels. End of iteration 10, added 4 new labels. Micro-averaged F1 score on test set: 0.834 ---------- LabelSpreading on 20% of the data (rest is unlabeled): Number of training samples: 2117 Unlabeled samples in training set: 1706 Micro-averaged F1 score on test set: 0.644 ---------- | .. code-block:: Python # Authors: The scikit-learn developers # SPDX-License-Identifier: BSD-3-Clause import numpy as np from sklearn.datasets import fetch_20newsgroups from sklearn.feature_extraction.text import CountVectorizer, TfidfTransformer from sklearn.linear_model import SGDClassifier from sklearn.metrics import f1_score from sklearn.model_selection import train_test_split from sklearn.pipeline import Pipeline from sklearn.preprocessing import FunctionTransformer from sklearn.semi_supervised import LabelSpreading, SelfTrainingClassifier # Loading dataset containing first five categories data = fetch_20newsgroups( subset="train", categories=[ "alt.atheism", "comp.graphics", "comp.os.ms-windows.misc", "comp.sys.ibm.pc.hardware", "comp.sys.mac.hardware", ], ) print("%d documents" % len(data.filenames)) print("%d categories" % len(data.target_names)) print() # Parameters sdg_params = dict(alpha=1e-5, penalty="l2", loss="log_loss") vectorizer_params = dict(ngram_range=(1, 2), min_df=5, max_df=0.8) # Supervised Pipeline pipeline = Pipeline( [ ("vect", CountVectorizer(**vectorizer_params)), ("tfidf", TfidfTransformer()), ("clf", SGDClassifier(**sdg_params)), ] ) # SelfTraining Pipeline st_pipeline = Pipeline( [ ("vect", CountVectorizer(**vectorizer_params)), ("tfidf", TfidfTransformer()), ("clf", SelfTrainingClassifier(SGDClassifier(**sdg_params), verbose=True)), ] ) # LabelSpreading Pipeline ls_pipeline = Pipeline( [ ("vect", CountVectorizer(**vectorizer_params)), ("tfidf", TfidfTransformer()), # LabelSpreading does not support dense matrices ("toarray", FunctionTransformer(lambda x: x.toarray())), ("clf", LabelSpreading()), ] ) def eval_and_print_metrics(clf, X_train, y_train, X_test, y_test): print("Number of training samples:", len(X_train)) print("Unlabeled samples in training set:", sum(1 for x in y_train if x == -1)) clf.fit(X_train, y_train) y_pred = clf.predict(X_test) print( "Micro-averaged F1 score on test set: %0.3f" % f1_score(y_test, y_pred, average="micro") ) print("-" * 10) print() if __name__ == "__main__": X, y = data.data, data.target X_train, X_test, y_train, y_test = train_test_split(X, y) print("Supervised SGDClassifier on 100% of the data:") eval_and_print_metrics(pipeline, X_train, y_train, X_test, y_test) # select a mask of 20% of the train dataset y_mask = np.random.rand(len(y_train)) < 0.2 # X_20 and y_20 are the subset of the train dataset indicated by the mask X_20, y_20 = map( list, zip(*((x, y) for x, y, m in zip(X_train, y_train, y_mask) if m)) ) print("Supervised SGDClassifier on 20% of the training data:") eval_and_print_metrics(pipeline, X_20, y_20, X_test, y_test) # set the non-masked subset to be unlabeled y_train[~y_mask] = -1 print("SelfTrainingClassifier on 20% of the training data (rest is unlabeled):") eval_and_print_metrics(st_pipeline, X_train, y_train, X_test, y_test) print("LabelSpreading on 20% of the data (rest is unlabeled):") eval_and_print_metrics(ls_pipeline, X_train, y_train, X_test, y_test) .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 6.517 seconds) .. _sphx_glr_download_auto_examples_semi_supervised_plot_semi_supervised_newsgroups.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: binder-badge .. image:: images/binder_badge_logo.svg :target: https://mybinder.org/v2/gh/scikit-learn/scikit-learn/main?urlpath=lab/tree/notebooks/auto_examples/semi_supervised/plot_semi_supervised_newsgroups.ipynb :alt: Launch binder :width: 150 px .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: plot_semi_supervised_newsgroups.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: plot_semi_supervised_newsgroups.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: plot_semi_supervised_newsgroups.zip ` .. include:: plot_semi_supervised_newsgroups.recommendations .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_