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

.. only:: html

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

        Click :ref:`here <sphx_glr_download_gallery_misc_svg_filter_line.py>`
        to download the full example code

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

.. _sphx_glr_gallery_misc_svg_filter_line.py:


===============
SVG Filter Line
===============

Demonstrate SVG filtering effects which might be used with mpl.

Note that the filtering effects are only effective if your svg renderer
support it.

.. GENERATED FROM PYTHON SOURCE LINES 11-88



.. image:: /gallery/misc/images/sphx_glr_svg_filter_line_001.png
    :alt: svg filter line
    :class: sphx-glr-single-img


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

 Out:

 .. code-block:: none

    Saving 'svg_filter_line.svg'






|

.. code-block:: default



    import matplotlib.pyplot as plt
    import matplotlib.transforms as mtransforms

    fig1 = plt.figure()
    ax = fig1.add_axes([0.1, 0.1, 0.8, 0.8])

    # draw lines
    l1, = ax.plot([0.1, 0.5, 0.9], [0.1, 0.9, 0.5], "bo-",
                  mec="b", lw=5, ms=10, label="Line 1")
    l2, = ax.plot([0.1, 0.5, 0.9], [0.5, 0.2, 0.7], "rs-",
                  mec="r", lw=5, ms=10, label="Line 2")


    for l in [l1, l2]:

        # draw shadows with same lines with slight offset and gray colors.

        xx = l.get_xdata()
        yy = l.get_ydata()
        shadow, = ax.plot(xx, yy)
        shadow.update_from(l)

        # adjust color
        shadow.set_color("0.2")
        # adjust zorder of the shadow lines so that it is drawn below the
        # original lines
        shadow.set_zorder(l.get_zorder() - 0.5)

        # offset transform
        ot = mtransforms.offset_copy(l.get_transform(), fig1,
                                     x=4.0, y=-6.0, units='points')

        shadow.set_transform(ot)

        # set the id for a later use
        shadow.set_gid(l.get_label() + "_shadow")


    ax.set_xlim(0., 1.)
    ax.set_ylim(0., 1.)

    # save the figure as a bytes string in the svg format.
    from io import BytesIO
    f = BytesIO()
    plt.savefig(f, format="svg")


    import xml.etree.ElementTree as ET

    # filter definition for a gaussian blur
    filter_def = """
      <defs xmlns='http://www.w3.org/2000/svg'
            xmlns:xlink='http://www.w3.org/1999/xlink'>
        <filter id='dropshadow' height='1.2' width='1.2'>
          <feGaussianBlur result='blur' stdDeviation='3'/>
        </filter>
      </defs>
    """


    # read in the saved svg
    tree, xmlid = ET.XMLID(f.getvalue())

    # insert the filter definition in the svg dom tree.
    tree.insert(0, ET.XML(filter_def))

    for l in [l1, l2]:
        # pick up the svg element with given id
        shadow = xmlid[l.get_label() + "_shadow"]
        # apply shadow filter
        shadow.set("filter", 'url(#dropshadow)')

    fn = "svg_filter_line.svg"
    print("Saving '%s'" % fn)
    ET.ElementTree(tree).write(fn)


.. _sphx_glr_download_gallery_misc_svg_filter_line.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: svg_filter_line.py <svg_filter_line.py>`



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

     :download:`Download Jupyter notebook: svg_filter_line.ipynb <svg_filter_line.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>`_