.. only:: html

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

        Click :ref:`here <sphx_glr_download_gallery_widgets_span_selector.py>`     to download the full example code
    .. rst-class:: sphx-glr-example-title

    .. _sphx_glr_gallery_widgets_span_selector.py:


=============
Span Selector
=============

The SpanSelector is a mouse widget to select a xmin/xmax range and plot the
detail view of the selected region in the lower axes


.. code-block:: default

    import numpy as np
    import matplotlib.pyplot as plt
    from matplotlib.widgets import SpanSelector

    # Fixing random state for reproducibility
    np.random.seed(19680801)

    fig, (ax1, ax2) = plt.subplots(2, figsize=(8, 6))
    ax1.set(facecolor='#FFFFCC')

    x = np.arange(0.0, 5.0, 0.01)
    y = np.sin(2*np.pi*x) + 0.5*np.random.randn(len(x))

    ax1.plot(x, y, '-')
    ax1.set_ylim(-2, 2)
    ax1.set_title('Press left mouse button and drag to test')

    ax2.set(facecolor='#FFFFCC')
    line2, = ax2.plot(x, y, '-')


    def onselect(xmin, xmax):
        indmin, indmax = np.searchsorted(x, (xmin, xmax))
        indmax = min(len(x) - 1, indmax)

        thisx = x[indmin:indmax]
        thisy = y[indmin:indmax]
        line2.set_data(thisx, thisy)
        ax2.set_xlim(thisx[0], thisx[-1])
        ax2.set_ylim(thisy.min(), thisy.max())
        fig.canvas.draw()




.. image:: /gallery/widgets/images/sphx_glr_span_selector_001.png
    :alt: Press left mouse button and drag to test
    :class: sphx-glr-single-img





.. note::

   If the SpanSelector object is garbage collected you will lose the
   interactivity.  You must keep a hard reference to it to prevent this.



.. code-block:: default



    span = SpanSelector(ax1, onselect, 'horizontal', useblit=True,
                        rectprops=dict(alpha=0.5, facecolor='red'))
    # Set useblit=True on most backends for enhanced performance.


    plt.show()








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

   **Total running time of the script:** ( 0 minutes  1.000 seconds)


.. _sphx_glr_download_gallery_widgets_span_selector.py:


.. only :: html

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



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

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



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

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


.. only:: html

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

    Keywords: matplotlib code example, codex, python plot, pyplot
    `Gallery generated by Sphinx-Gallery
    <https://sphinx-gallery.readthedocs.io>`_