.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "auto_examples/linear_model/plot_robust_fit.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_linear_model_plot_robust_fit.py: Robust linear estimator fitting =============================== Here a sine function is fit with a polynomial of order 3, for values close to zero. Robust fitting is demoed in different situations: - No measurement errors, only modelling errors (fitting a sine with a polynomial) - Measurement errors in X - Measurement errors in y The median absolute deviation to non corrupt new data is used to judge the quality of the prediction. What we can see that: - RANSAC is good for strong outliers in the y direction - TheilSen is good for small outliers, both in direction X and y, but has a break point above which it performs worse than OLS. - The scores of HuberRegressor may not be compared directly to both TheilSen and RANSAC because it does not attempt to completely filter the outliers but lessen their effect. .. GENERATED FROM PYTHON SOURCE LINES 32-120 .. rst-class:: sphx-glr-horizontal * .. image-sg:: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_001.png :alt: Modeling Errors Only :srcset: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_001.png :class: sphx-glr-multi-img * .. image-sg:: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_002.png :alt: Corrupt X, Small Deviants :srcset: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_002.png :class: sphx-glr-multi-img * .. image-sg:: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_003.png :alt: Corrupt y, Small Deviants :srcset: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_003.png :class: sphx-glr-multi-img * .. image-sg:: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_004.png :alt: Corrupt X, Large Deviants :srcset: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_004.png :class: sphx-glr-multi-img * .. image-sg:: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_005.png :alt: Corrupt y, Large Deviants :srcset: /auto_examples/linear_model/images/sphx_glr_plot_robust_fit_005.png :class: sphx-glr-multi-img .. code-block:: Python # Authors: The scikit-learn developers # SPDX-License-Identifier: BSD-3-Clause import numpy as np from matplotlib import pyplot as plt from sklearn.linear_model import ( HuberRegressor, LinearRegression, RANSACRegressor, TheilSenRegressor, ) from sklearn.metrics import mean_squared_error from sklearn.pipeline import make_pipeline from sklearn.preprocessing import PolynomialFeatures np.random.seed(42) X = np.random.normal(size=400) y = np.sin(X) # Make sure that it X is 2D X = X[:, np.newaxis] X_test = np.random.normal(size=200) y_test = np.sin(X_test) X_test = X_test[:, np.newaxis] y_errors = y.copy() y_errors[::3] = 3 X_errors = X.copy() X_errors[::3] = 3 y_errors_large = y.copy() y_errors_large[::3] = 10 X_errors_large = X.copy() X_errors_large[::3] = 10 estimators = [ ("OLS", LinearRegression()), ("Theil-Sen", TheilSenRegressor(random_state=42)), ("RANSAC", RANSACRegressor(random_state=42)), ("HuberRegressor", HuberRegressor()), ] colors = { "OLS": "turquoise", "Theil-Sen": "gold", "RANSAC": "lightgreen", "HuberRegressor": "black", } linestyle = {"OLS": "-", "Theil-Sen": "-.", "RANSAC": "--", "HuberRegressor": "--"} lw = 3 x_plot = np.linspace(X.min(), X.max()) for title, this_X, this_y in [ ("Modeling Errors Only", X, y), ("Corrupt X, Small Deviants", X_errors, y), ("Corrupt y, Small Deviants", X, y_errors), ("Corrupt X, Large Deviants", X_errors_large, y), ("Corrupt y, Large Deviants", X, y_errors_large), ]: plt.figure(figsize=(5, 4)) plt.plot(this_X[:, 0], this_y, "b+") for name, estimator in estimators: model = make_pipeline(PolynomialFeatures(3), estimator) model.fit(this_X, this_y) mse = mean_squared_error(model.predict(X_test), y_test) y_plot = model.predict(x_plot[:, np.newaxis]) plt.plot( x_plot, y_plot, color=colors[name], linestyle=linestyle[name], linewidth=lw, label="%s: error = %.3f" % (name, mse), ) legend_title = "Error of Mean\nAbsolute Deviation\nto Non-corrupt Data" legend = plt.legend( loc="upper right", frameon=False, title=legend_title, prop=dict(size="x-small") ) plt.xlim(-4, 10.2) plt.ylim(-2, 10.2) plt.title(title) plt.show() .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 1.661 seconds) .. _sphx_glr_download_auto_examples_linear_model_plot_robust_fit.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/linear_model/plot_robust_fit.ipynb :alt: Launch binder :width: 150 px .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: plot_robust_fit.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: plot_robust_fit.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: plot_robust_fit.zip ` .. include:: plot_robust_fit.recommendations .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_