Descartes =========

    Use Shapely_ or GeoJSON-like geometric objects as matplotlib paths and patches

    .. image:: http://farm4.static.flickr.com/3662/4555372019_9bbed1f956_o_d.png
       :width: 800
       :height: 320

    Requires: matplotlib, numpy, and optionally Shapely 1.2+.

    Example::

      from matplotlib import pyplot
      from shapely.geometry import LineString
      from descartes import PolygonPatch

      BLUE = '#6699cc'
      GRAY = '#999999'

      def plot_line(ax, ob):
          x, y = ob.xy
          ax.plot(x, y, color=GRAY, linewidth=3, solid_capstyle='round', zorder=1)

      line = LineString([(0, 0), (1, 1), (0, 2), (2, 2), (3, 1), (1, 0)])

      fig = pyplot.figure(1, figsize=(10, 4), dpi=180)

      # 1
      ax = fig.add_subplot(121)

      plot_line(ax, line)

      dilated = line.buffer(0.5)
      patch1 = PolygonPatch(dilated, fc=BLUE, ec=BLUE, alpha=0.5, zorder=2)
      ax.add_patch(patch1)

      #2
      ax = fig.add_subplot(122)

      patch2a = PolygonPatch(dilated, fc=GRAY, ec=GRAY, alpha=0.5, zorder=1)
      ax.add_patch(patch2a)

      eroded = dilated.buffer(-0.3)

      # GeoJSON-like data works as well

      polygon = eroded.__geo_interface__
      # >>> geo['type']
      # 'Polygon'
      # >>> geo['coordinates'][0][:2]
      # ((0.50502525316941682, 0.78786796564403572), (0.5247963548222736, 0.8096820147509064))
      patch2b = PolygonPatch(polygon, fc=BLUE, ec=BLUE, alpha=0.5, zorder=2)
      ax.add_patch(patch2b)

      pyplot.show()


    See also: examples/patches.py.

    Descartes is not associated with the identically named and apparently defunct
    project at http://descartes.sourceforge.net/.

    .. _Shapely: http://gispython.org/lab/wiki/Shapely