GeoDjango: getting a random point within a multipolygon

Django

GeoDjango: getting a random point within a multipolygon

While fooling around with the awesome GeoDjango framework, I was looking for a way to generate a random point within a multipolygon.

Justin Bronn (djangopeople.net/jbronn/), the lead developer of GeoDjango was kind enough to point me in the right direction. I thought I share the concept here as it might be helpful to someone:

Define the function:

def get_random_point(extent):
   xrange = extent[2] - extent[0]
   yrange = extent[3] - extent[1]
   randx = xrange * random.random() + extent[0]
   randy = yrange * random.random() + extent[1]
   return Point(randx, randy)

And then:

extent = mpoly.extent
pnt = get_random_point(extent)
while not mpoly.contains(pnt):
   pnt = get_randomPoint(extent)

Let me know what you think or if you’ve got any improvements!

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