Note
Click here to download the full example code
This example presents the different strategies implemented in KBinsDiscretizer:
The plot shows the regions where the discretized encoding is constant.
# Author: Tom Dupré la Tour # License: BSD 3 clause import numpy as np import matplotlib.pyplot as plt from sklearn.preprocessing import KBinsDiscretizer from sklearn.datasets import make_blobs print(__doc__) strategies = ['uniform', 'quantile', 'kmeans'] n_samples = 200 centers_0 = np.array([[0, 0], [0, 5], [2, 4], [8, 8]]) centers_1 = np.array([[0, 0], [3, 1]]) # construct the datasets random_state = 42 X_list = [ np.random.RandomState(random_state).uniform(-3, 3, size=(n_samples, 2)), make_blobs(n_samples=[n_samples // 10, n_samples * 4 // 10, n_samples // 10, n_samples * 4 // 10], cluster_std=0.5, centers=centers_0, random_state=random_state)[0], make_blobs(n_samples=[n_samples // 5, n_samples * 4 // 5], cluster_std=0.5, centers=centers_1, random_state=random_state)[0], ] figure = plt.figure(figsize=(14, 9)) i = 1 for ds_cnt, X in enumerate(X_list): ax = plt.subplot(len(X_list), len(strategies) + 1, i) ax.scatter(X[:, 0], X[:, 1], edgecolors='k') if ds_cnt == 0: ax.set_title("Input data", size=14) xx, yy = np.meshgrid( np.linspace(X[:, 0].min(), X[:, 0].max(), 300), np.linspace(X[:, 1].min(), X[:, 1].max(), 300)) grid = np.c_[xx.ravel(), yy.ravel()] ax.set_xlim(xx.min(), xx.max()) ax.set_ylim(yy.min(), yy.max()) ax.set_xticks(()) ax.set_yticks(()) i += 1 # transform the dataset with KBinsDiscretizer for strategy in strategies: enc = KBinsDiscretizer(n_bins=4, encode='ordinal', strategy=strategy) enc.fit(X) grid_encoded = enc.transform(grid) ax = plt.subplot(len(X_list), len(strategies) + 1, i) # horizontal stripes horizontal = grid_encoded[:, 0].reshape(xx.shape) ax.contourf(xx, yy, horizontal, alpha=.5) # vertical stripes vertical = grid_encoded[:, 1].reshape(xx.shape) ax.contourf(xx, yy, vertical, alpha=.5) ax.scatter(X[:, 0], X[:, 1], edgecolors='k') ax.set_xlim(xx.min(), xx.max()) ax.set_ylim(yy.min(), yy.max()) ax.set_xticks(()) ax.set_yticks(()) if ds_cnt == 0: ax.set_title("strategy='%s'" % (strategy, ), size=14) i += 1 plt.tight_layout() plt.show()
Total running time of the script: ( 0 minutes 0.663 seconds)
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http://scikit-learn.org/stable/auto_examples/preprocessing/plot_discretization_strategies.html