>>> """
==========
Hatch demo
==========

Hatches can be added to most polygons in Matplotlib, including `~.Axes.bar`,
`~.Axes.fill_between`, `~.Axes.contourf`, and children of `~.patches.Polygon`.
They are currently supported in the PS, PDF, SVG, OSX, and Agg backends. The WX
and Cairo backends do not currently support hatching.

See also :doc:`/gallery/images_contours_and_fields/contourf_hatching` for
an example using `~.Axes.contourf`, and
:doc:`/gallery/shapes_and_collections/hatch_style_reference` for swatches
of the existing hatches.

"""
... 
... import numpy as np
... import matplotlib.pyplot as plt
... from matplotlib.patches import Ellipse, Polygon
... 
... x = np.arange(1, 5)
... y1 = np.arange(1, 5)
... y2 = np.ones(y1.shape) * 4
... 
... fig = plt.figure()
... axs = fig.subplot_mosaic([['bar1', 'patches'], ['bar2', 'patches']])
... 
... axs['bar1'].bar(x, y1, edgecolor='black', hatch="/")
... axs['bar1'].bar(x, y2, bottom=y1, edgecolor='black', hatch='//')
... 
... axs['bar2'].bar(x, y1, edgecolor='black', hatch=['--', '+', 'x', '\\'])
... axs['bar2'].bar(x, y2, bottom=y1, edgecolor='black',
...                 hatch=['*', 'o', 'O', '.'])
... 
... x = np.arange(0, 40, 0.2)
... axs['patches'].fill_between(x, np.sin(x) * 4 + 30, y2=0,
...                             hatch='///', zorder=2, fc='c')
... axs['patches'].add_patch(Ellipse((4, 50), 10, 10, fill=True,
...                                  hatch='*', facecolor='y'))
... axs['patches'].add_patch(Polygon([(10, 20), (30, 50), (50, 10)],
...                                  hatch='\\/...', facecolor='g'))
... axs['patches'].set_xlim([0, 40])
... axs['patches'].set_ylim([10, 60])
... axs['patches'].set_aspect(1)
... plt.show()
... 
... #############################################################################
... #
... # .. admonition:: References
... #
... #    The use of the following functions, methods, classes and modules is shown
... #    in this example:
... #
... #    - `matplotlib.patches`
... #    - `matplotlib.patches.Ellipse`
... #    - `matplotlib.patches.Polygon`
... #    - `matplotlib.axes.Axes.add_patch`
... #    - `matplotlib.patches.Patch.set_hatch`
... #    - `matplotlib.axes.Axes.bar` / `matplotlib.pyplot.bar`
...