.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "auto_examples/svm/plot_separating_hyperplane_unbalanced.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 JupyterLite or Binder .. rst-class:: sphx-glr-example-title .. _sphx_glr_auto_examples_svm_plot_separating_hyperplane_unbalanced.py: ================================================= SVM: Separating hyperplane for unbalanced classes ================================================= Find the optimal separating hyperplane using an SVC for classes that are unbalanced. We first find the separating plane with a plain SVC and then plot (dashed) the separating hyperplane with automatically correction for unbalanced classes. .. currentmodule:: sklearn.linear_model .. note:: This example will also work by replacing ``SVC(kernel="linear")`` with ``SGDClassifier(loss="hinge")``. Setting the ``loss`` parameter of the :class:`SGDClassifier` equal to ``hinge`` will yield behaviour such as that of a SVC with a linear kernel. For example try instead of the ``SVC``:: clf = SGDClassifier(n_iter=100, alpha=0.01) .. GENERATED FROM PYTHON SOURCE LINES 27-93 .. image-sg:: /auto_examples/svm/images/sphx_glr_plot_separating_hyperplane_unbalanced_001.png :alt: plot separating hyperplane unbalanced :srcset: /auto_examples/svm/images/sphx_glr_plot_separating_hyperplane_unbalanced_001.png :class: sphx-glr-single-img .. code-block:: Python import matplotlib.lines as mlines import matplotlib.pyplot as plt from sklearn import svm from sklearn.datasets import make_blobs from sklearn.inspection import DecisionBoundaryDisplay # we create two clusters of random points n_samples_1 = 1000 n_samples_2 = 100 centers = [[0.0, 0.0], [2.0, 2.0]] clusters_std = [1.5, 0.5] X, y = make_blobs( n_samples=[n_samples_1, n_samples_2], centers=centers, cluster_std=clusters_std, random_state=0, shuffle=False, ) # fit the model and get the separating hyperplane clf = svm.SVC(kernel="linear", C=1.0) clf.fit(X, y) # fit the model and get the separating hyperplane using weighted classes wclf = svm.SVC(kernel="linear", class_weight={1: 10}) wclf.fit(X, y) # plot the samples plt.scatter(X[:, 0], X[:, 1], c=y, cmap=plt.cm.Paired, edgecolors="k") # plot the decision functions for both classifiers ax = plt.gca() disp = DecisionBoundaryDisplay.from_estimator( clf, X, plot_method="contour", colors="k", levels=[0], alpha=0.5, linestyles=["-"], ax=ax, ) # plot decision boundary and margins for weighted classes wdisp = DecisionBoundaryDisplay.from_estimator( wclf, X, plot_method="contour", colors="r", levels=[0], alpha=0.5, linestyles=["-"], ax=ax, ) plt.legend( [ mlines.Line2D([], [], color="k", label="non weighted"), mlines.Line2D([], [], color="r", label="weighted"), ], ["non weighted", "weighted"], loc="upper right", ) plt.show() .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 0.168 seconds) .. _sphx_glr_download_auto_examples_svm_plot_separating_hyperplane_unbalanced.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/svm/plot_separating_hyperplane_unbalanced.ipynb :alt: Launch binder :width: 150 px .. container:: lite-badge .. image:: images/jupyterlite_badge_logo.svg :target: ../../lite/lab/?path=auto_examples/svm/plot_separating_hyperplane_unbalanced.ipynb :alt: Launch JupyterLite :width: 150 px .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: plot_separating_hyperplane_unbalanced.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: plot_separating_hyperplane_unbalanced.py ` .. include:: plot_separating_hyperplane_unbalanced.recommendations .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_