.. _sphx_glr_auto_examples_cluster_plot_mean_shift.py:


=============================================
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.



.. code-block:: python

    print(__doc__)

    import numpy as np
    from sklearn.cluster import MeanShift, estimate_bandwidth
    from sklearn.datasets.samples_generator import make_blobs







Generate sample data


.. code-block:: python

    centers = [[1, 1], [-1, -1], [1, -1]]
    X, _ = make_blobs(n_samples=10000, centers=centers, cluster_std=0.6)







Compute clustering with MeanShift


.. code-block:: python


    # 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_)





.. rst-class:: sphx-glr-script-out

 Out::

      number of estimated clusters : 3


Plot result


.. code-block:: python

    import matplotlib.pyplot as plt
    from itertools import cycle

    plt.figure(1)
    plt.clf()

    colors = cycle('bgrcmykbgrcmykbgrcmykbgrcmyk')
    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], col + '.')
        plt.plot(cluster_center[0], cluster_center[1], 'o', markerfacecolor=col,
                 markeredgecolor='k', markersize=14)
    plt.title('Estimated number of clusters: %d' % n_clusters_)
    plt.show()



.. image:: /auto_examples/cluster/images/sphx_glr_plot_mean_shift_001.png
    :align: center




**Total running time of the script:**
(0 minutes 1.117 seconds)



.. container:: sphx-glr-download

    **Download Python source code:** :download:`plot_mean_shift.py <plot_mean_shift.py>`


.. container:: sphx-glr-download

    **Download IPython notebook:** :download:`plot_mean_shift.ipynb <plot_mean_shift.ipynb>`