def get_polygons(self):
""" Return campaign's area as Shapely Polygon.
:return: Polygons
:rtype: list
"""
campaign_polygons = []
for feature in self.geometry['features']:
polygon = geometry.Polygon(feature['geometry']['coordinates'][0])
campaign_polygons.append(polygon)
return campaign_polygons
def get_union_polygons(self):
"""Return union polygons"""
simplify = False
if len(self.geometry['features']) > 1:
polygons = []
for feature in self.geometry['features']:
polygons.append(
geometry.Polygon(feature['geometry']['coordinates'][0]))
cascaded_polygons = ops.cascaded_union(polygons)
simplify = True
else:
cascaded_polygons = geometry.Polygon(
self.geometry['features'][0]['geometry']['coordinates'][0])
joined_polygons = cascaded_polygons.buffer(
0.001, 1, join_style=geometry.JOIN_STYLE.mitre).buffer(
-0.001, 1, join_style=geometry.JOIN_STYLE.mitre)
if simplify:
joined_polygons = simplify_polygon(joined_polygons, 0.001)
return joined_polygons
def find_outside_polygons(file, campaign_polygons):
""" Find polygons outside the campaign's area
:param file: the OSM file
:type file: fd
:param campaign_polygons: campaign's areas as Shapely Polygons
:type campaign_polygons: list of Shapely Polygon
:return out_ids: ids of nodes and ways that are outside campaign's areas.
:rtype: dictionary
"""
nodes = {}
ways = {}
in_way = False
out_ids = {'nodes': [], 'ways': []}
for event, elem in ET.iterparse(file, events=('start', 'end')):
# start of a node element
# store its id, lon and lat
if elem.tag == 'node' and event == 'start':
nodes[elem.attrib['id']] = {
'id': elem.attrib['id'],
'lon': elem.attrib['lon'],
'lat': elem.attrib['lat']
}
# start of way element
if elem.tag == 'way' and event == 'start':
# create a new way
ways[elem.attrib['id']] = []
in_way = True
way_id = elem.attrib['id']
# nd element in a way element
if elem.tag == 'nd' and in_way is True:
# fetch the node
node = nodes[elem.attrib['ref']]
ways[way_id].append(node)
# end of way element
if elem.tag == 'way' and event == 'end':
in_way = False
# create a shapely polygon
polygon = []
for point in ways[way_id]:
polygon.append((float(point['lon']), float(point['lat'])))
polygon = geometry.Polygon(polygon)
# is the polygon in one of the campaign's polygons?
is_in = False
for campaign_polygon in campaign_polygons:
if campaign_polygon.contains(polygon):
is_in = True
if not is_in:
node_ids = list(map(lambda x: x['id'], ways[way_id]))
for node_id in node_ids:
out_ids['nodes'].append(node_id)
out_ids['ways'].append(way_id)
return out_ids