sklearn/examples/cluster/plot_mean_shift.py

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2024-08-05 09:32:03 +02:00
"""
=============================================
A demo of the mean-shift clustering algorithm
=============================================
Reference:
Dorin Comaniciu and Peter Meer, "Mean Shift: A robust approach toward
feature space analysis". IEEE Transactions on Pattern Analysis and
Machine Intelligence. 2002. pp. 603-619.
"""
import numpy as np
from sklearn.cluster import MeanShift, estimate_bandwidth
from sklearn.datasets import make_blobs
# %%
# Generate sample data
# --------------------
centers = [[1, 1], [-1, -1], [1, -1]]
X, _ = make_blobs(n_samples=10000, centers=centers, cluster_std=0.6)
# %%
# Compute clustering with MeanShift
# ---------------------------------
# The following bandwidth can be automatically detected using
bandwidth = estimate_bandwidth(X, quantile=0.2, n_samples=500)
ms = MeanShift(bandwidth=bandwidth, bin_seeding=True)
ms.fit(X)
labels = ms.labels_
cluster_centers = ms.cluster_centers_
labels_unique = np.unique(labels)
n_clusters_ = len(labels_unique)
print("number of estimated clusters : %d" % n_clusters_)
# %%
# Plot result
# -----------
import matplotlib.pyplot as plt
plt.figure(1)
plt.clf()
colors = ["#dede00", "#377eb8", "#f781bf"]
markers = ["x", "o", "^"]
for k, col in zip(range(n_clusters_), colors):
my_members = labels == k
cluster_center = cluster_centers[k]
plt.plot(X[my_members, 0], X[my_members, 1], markers[k], color=col)
plt.plot(
cluster_center[0],
cluster_center[1],
markers[k],
markerfacecolor=col,
markeredgecolor="k",
markersize=14,
)
plt.title("Estimated number of clusters: %d" % n_clusters_)
plt.show()