def connect_with_nearest_street(self, poi_node, streets, projection_threshold):
""" Tries to connect a selected point of interest with the nearest streets
The method looks in a list of streets for the neareast street and connects the poi and this street.
@type poi_node: L{geo.osm_import.Node}
@param poi_node: the OSM Node object that shall be connected with the street network
@param streets: list of L{geo.osm_import.Way} objects that are streets
@param projection_threshold: distance in meters that a connection to the next node may be longer than a direct connection by projection
@returns: True if the connection was successful, False otherwise
@rtype: C{bool}
"""
connected = False
# connection fails if the street list is empty or None
if not streets:
return False
nearest_street, street_distance, nearest_mode = get_nearest_street(poi_node, streets)
# for explanation of the distance_mode see geo.geo_utils.__distance_point_to_line
# connect to nearest node if no projection is possible
if len(nearest_mode) == 1:
connected = connect_by_node(self.__osm_object, poi_node, nearest_mode[0])
else:
nearest_node, node_distance = get_nearest_street_node(poi_node, [nearest_street])
if node_distance - street_distance < projection_threshold:
connected = connect_by_node(self.__osm_object, poi_node, nearest_node)
else:
connected = connect_by_projection(self.__osm_object, poi_node, nearest_street, nearest_mode)
return connected
def connect_partition(self, partition_id, thresholds):
""" Initializes the connection of a single partition given by its partition id with the street network
@type partition_id: C{int}
@param partition_id: partition id
@param thresholds: a dictionary containing search distance, projection threshold, size threshold, connection threshold and distance threshold { 'search':svalue, 'projection':pvalue, 'size':sivalue, 'connection':cvalue, 'distance':dvalue }
@returns: True if the partition was successfully connected with the street network
@rtype: C{bool}
"""
search_threshold = int(thresholds.get('search'))
projection_threshold = int(thresholds.get('projection'))
size_threshold = int(thresholds.get('size'))
connection_threshold = int(thresholds.get('connection'))
distance_threshold = int(thresholds.get('distance'))
partition = self.__partitions.get(partition_id)
if partition.partition_size_by_nodes() < size_threshold:
self.remove_partition(partition)
return True
#nearest_street = None
min_distance = 1e400
#min_mode = None
nearest_part_node = None
nodes_and_distances = []
new_partition_id = 0
# saves the nodes that have already been connected to another partition
connected_nodes = []
for node in partition.nodes:
streets = self.__osm_object.get_adjacent_streets(node, search_threshold)
streets = self.filter_streets_by_partition(streets, partition_id)
# TODO: remove debug message
#if DEBUG:
# print node, get_nearest_street(node, streets)
street, distance, mode = get_nearest_street(node, streets)
if street:
nodes_and_distances.append((distance, node, street))
sorted_nodes_by_distances = sorted(nodes_and_distances)
partition_connected = False
connection_count = 0
index = 0
while connection_count < connection_threshold:
if index >= len(sorted_nodes_by_distances):
break
connected = False
min_distance, nearest_part_node, nearest_street = sorted_nodes_by_distances[index]
index += 1
ignore = False
for connected_node in connected_nodes:
az_f, az_b, distance = distance_points(nearest_part_node, connected_node)
if distance < distance_threshold:
ignore = True
if not ignore:
nearest_street, dist, min_mode = get_nearest_street(nearest_part_node, [nearest_street])
if len(min_mode) == 1:
connected = connect_by_node(self.__osm_object, nearest_part_node, min_mode[0])
if connected:
new_partition_id = min_mode[0].partition_id
partition.add_street(connected)
else:
nearest_street_node, node_distance = get_nearest_street_node(nearest_part_node, [nearest_street])
if node_distance - min_distance < projection_threshold:
connected = connect_by_node(self.__osm_object, nearest_part_node, nearest_street_node)
if connected:
new_partition_id = nearest_street_node.partition_id
partition.add_street(connected)
else:
connected = connect_by_projection(self.__osm_object, nearest_part_node, nearest_street, min_mode)
if connected:
new_partition_id = nearest_street.partition_id
partition.add_street(connected)
if connected:
connected_nodes.append(nearest_part_node)
connection_count += 1
partition_connected = partition_connected or connected
# merge the joined partitions to one partition
if partition_connected:
new_partition = self.__partitions.get(new_partition_id)
# TODO: remove debug message
if DEBUG:
if new_partition == None:
print new_partition_id
print thresholds
new_partition.append_partition(partition)
del self.__partitions[partition_id]
del partition
return partition_connected