.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "intro/scipy/auto_examples/plot_connect_measurements.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_intro_scipy_auto_examples_plot_connect_measurements.py>`
        to download the full example code

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_intro_scipy_auto_examples_plot_connect_measurements.py:


=============================
Demo connected components
=============================

Extracting and labeling connected components in a 2D array

.. GENERATED FROM PYTHON SOURCE LINES 8-12

.. code-block:: default


    import numpy as np
    import matplotlib.pyplot as plt








.. GENERATED FROM PYTHON SOURCE LINES 13-14

Generate some binary data

.. GENERATED FROM PYTHON SOURCE LINES 14-32

.. code-block:: default

    np.random.seed(0)
    x, y = np.indices((100, 100))
    sig = np.sin(2*np.pi*x/50.) * np.sin(2*np.pi*y/50.) * (1+x*y/50.**2)**2
    mask = sig > 1

    plt.figure(figsize=(7, 3.5))
    plt.subplot(1, 2, 1)
    plt.imshow(sig)
    plt.axis('off')
    plt.title('sig')

    plt.subplot(1, 2, 2)
    plt.imshow(mask, cmap=plt.cm.gray)
    plt.axis('off')
    plt.title('mask')
    plt.subplots_adjust(wspace=.05, left=.01, bottom=.01, right=.99, top=.9)





.. image-sg:: /intro/scipy/auto_examples/images/sphx_glr_plot_connect_measurements_001.png
   :alt: sig, mask
   :srcset: /intro/scipy/auto_examples/images/sphx_glr_plot_connect_measurements_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 33-34

Label connected components

.. GENERATED FROM PYTHON SOURCE LINES 34-45

.. code-block:: default

    import scipy as sp
    labels, nb = sp.ndimage.label(mask)

    plt.figure(figsize=(3.5, 3.5))
    plt.imshow(labels)
    plt.title('label')
    plt.axis('off')

    plt.subplots_adjust(wspace=.05, left=.01, bottom=.01, right=.99, top=.9)





.. image-sg:: /intro/scipy/auto_examples/images/sphx_glr_plot_connect_measurements_002.png
   :alt: label
   :srcset: /intro/scipy/auto_examples/images/sphx_glr_plot_connect_measurements_002.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 46-47

Extract the 4th connected component, and crop the array around it

.. GENERATED FROM PYTHON SOURCE LINES 47-56

.. code-block:: default

    sl = sp.ndimage.find_objects(labels==4)
    plt.figure(figsize=(3.5, 3.5))
    plt.imshow(sig[sl[0]])
    plt.title('Cropped connected component')
    plt.axis('off')

    plt.subplots_adjust(wspace=.05, left=.01, bottom=.01, right=.99, top=.9)

    plt.show()



.. image-sg:: /intro/scipy/auto_examples/images/sphx_glr_plot_connect_measurements_003.png
   :alt: Cropped connected component
   :srcset: /intro/scipy/auto_examples/images/sphx_glr_plot_connect_measurements_003.png
   :class: sphx-glr-single-img






.. rst-class:: sphx-glr-timing

   **Total running time of the script:** ( 0 minutes  0.112 seconds)


.. _sphx_glr_download_intro_scipy_auto_examples_plot_connect_measurements.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example




    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_connect_measurements.py <plot_connect_measurements.py>`

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_connect_measurements.ipynb <plot_connect_measurements.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_