A decision tree is boosted using the AdaBoost.R2 [1] algorithm on a 1D sinusoidal dataset with a small amount of Gaussian noise. 299 boosts (300 decision trees) is compared with a single decision tree regressor. As the number of boosts is increased the regressor can fit more detail.
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print(__doc__) # Author: Noel Dawe <noel.dawe@gmail.com> # # License: BSD 3 clause # importing necessary libraries import numpy as np import matplotlib.pyplot as plt from sklearn.tree import DecisionTreeRegressor from sklearn.ensemble import AdaBoostRegressor # Create the dataset rng = np.random.RandomState(1) X = np.linspace(0, 6, 100)[:, np.newaxis] y = np.sin(X).ravel() + np.sin(6 * X).ravel() + rng.normal(0, 0.1, X.shape[0]) # Fit regression model regr_1 = DecisionTreeRegressor(max_depth=4) regr_2 = AdaBoostRegressor(DecisionTreeRegressor(max_depth=4), n_estimators=300, random_state=rng) regr_1.fit(X, y) regr_2.fit(X, y) # Predict y_1 = regr_1.predict(X) y_2 = regr_2.predict(X) # Plot the results plt.figure() plt.scatter(X, y, c="k", label="training samples") plt.plot(X, y_1, c="g", label="n_estimators=1", linewidth=2) plt.plot(X, y_2, c="r", label="n_estimators=300", linewidth=2) plt.xlabel("data") plt.ylabel("target") plt.title("Boosted Decision Tree Regression") plt.legend() plt.show()
Total running time of the script: (0 minutes 0.742 seconds)
Download Python source code:
plot_adaboost_regression.py
Download IPython notebook:
plot_adaboost_regression.ipynb
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