AdaBoost with Logistic Regressions gives wrong separating surface

I want to use AdaBoost with LogisticRegressions, but the separating surface is wrong.enter image description here

from sklearn.linear_model import LogisticRegression
from sklearn.datasets import make_circles
from sklearn.ensemble import AdaBoostClassifier
import numpy as np
import matplotlib.pyplot as plt
import pylab

X, y = make_circles(n_samples=1000, random_state=123, noise=0.3, factor=0.2)
clf = AdaBoostClassifier(base_estimator=LogisticRegression(), n_estimators=10)
clf.fit(X, y);
x_grid, y_grid = np.meshgrid(np.linspace(-1.2, 1.2, 300), np.linspace(-1.2, 1.2, 300))
xy = np.stack([x_grid, y_grid], axis=2).reshape(-1, 2)
predicted = clf.predict(xy)
plt.figure(figsize=(16, 9))
plt.scatter(xy[:, 0], xy[:, 1], c=predicted, alpha=0.4, s=1)
plt.scatter(X[:, 0], X[:, 1], c=y, s=80)
pylab.ylim (-1.2, 1.2)
pylab.xlim(-1.2, 1.2);
How many English words
do you know?
Test your English vocabulary size, and measure
how many words do you know
Online Test
Powered by Examplum