descartes 1.0

descartes is a Python module that allows you to use Shapely or GeoJSON-like geometric objects as matplotlib paths and patches.

Example:

from matplotlib import pyplot
from shapely.geometry import LineString

from descartes.patch import PolygonPatch

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

fig = pyplot.figure(1, figsize=(7.5, 3), dpi=180)

# 1
ax = fig.add_subplot(121)

dilated = line.buffer(0.5)
patch1 = PolygonPatch(dilated, facecolor='#99ccff', edgecolor='#6699cc')
ax.add_patch(patch1)

x, y = line.xy
ax.plot(x, y, color='#999999')

ax.set_xlim(-1, 4)
ax.set_ylim(-1, 3)

#2
ax = fig.add_subplot(122)

patch2a = PolygonPatch(dilated, facecolor='#cccccc', edgecolor='#999999')
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, facecolor='#99ccff', edgecolor='#6699cc')
ax.add_patch(patch2b)

ax.set_xlim(-1, 4)
ax.set_ylim(-1, 3)

fig.subplots_adjust(0.0, 0.0, 1.0, 1.0, 0.1)
fig.savefig('buffering.png')

See also: examples/patches.py.


Product's homepage

Requirements:

· Python
· Matplotlib
· NumPy
· Shapely