def bbox_polygon(bbox: list, properties: dict = {}) -> Feature:
"""
To generate a Polygon Feature for the bounding box generated using bbox.
:param bbox: bounding box generated for a geojson.
:param properties: properties to be added to the returned feature.
:return: polygon for the given bounding box coordinates.
Example :
>>> from turfpy.measurement import bbox_polygon, bbox
>>> from geojson import Polygon
>>> p = Polygon([((2.38, 57.322), (23.194, -20.28), (-120.43, 19.15),
... (2.38, 57.322))])
>>> bb = bbox(p)
>>> feature = bbox_polygon(bb)
"""
west = float(bbox[0])
south = float(bbox[1])
east = float(bbox[2])
north = float(bbox[3])
if len(bbox) == 6:
raise Exception("bbox-polygon does not support BBox with 6 positions")
low_left = (west, south)
top_left = (west, north)
top_right = (east, north)
low_right = (east, south)
bbox_polygon = Polygon([(low_left, low_right, top_right, top_left,
low_left)])
feature_bbox = Feature(geometry=bbox_polygon)
if "properties" in properties:
feature_bbox.properties = properties["properties"]
elif "properties" not in properties:
feature_bbox.properties = {}
if "id" in properties:
feature_bbox.id = properties["id"]
if "bbox" in properties:
feature_bbox.bbox = properties["bbox"]
return feature_bbox
def center(geojson, properties: Optional[dict] = None) -> Feature:
"""
Takes a Feature or FeatureCollection and returns the absolute center point of all
features.
:param geojson: GeoJSON for which centered to be calculated.
:param properties: Optional parameters to be set to the generated feature.
:return: Point feature for the center.
Example :
>>> from turfpy.measurement import center
>>> from geojson import Feature, FeatureCollection, Point
>>> f1 = Feature(geometry=Point((-97.522259, 35.4691)))
>>> f2 = Feature(geometry=Point((-97.502754, 35.463455)))
>>> f3 = Feature(geometry=Point((-97.508269, 35.463245)))
>>> feature_collection = FeatureCollection([f1, f2, f3])
>>> feature = center(feature_collection)
"""
bounding_box = bbox(geojson)
x = (bounding_box[0] + bounding_box[2]) / 2
y = (bounding_box[1] + bounding_box[3]) / 2
point = Point((x, y))
center_feature = Feature(geometry=point)
if properties is None:
properties = dict()
if "properties" in properties:
center_feature.properties = properties["properties"]
elif "properties" not in properties:
center_feature.properties = {}
if "id" in properties:
center_feature.id = properties["id"]
if "bbox" in properties:
center_feature.bbox = properties["bbox"]
return center_feature
def add_geojson(self, json_ld):
"""
adds geospatial and event data that links time and space information
"""
uuid = self.manifest.uuid
item_type = self.manifest.item_type
geo_meta = self.geo_meta
event_meta = self.event_meta
features_dict = False # dict of all features to be added
feature_events = False # mappings between features and time periods
if geo_meta is not False:
# print('here!' + str(geo_meta))
features_dict = LastUpdatedOrderedDict()
feature_events = LastUpdatedOrderedDict()
for geo in geo_meta:
geo_id = geo.feature_id
geo_node = '#geo-' + str(
geo_id) # the node id for database rec of the feature
geo_node_geom = '#geo-geom-' + str(geo_id)
geo_node_props = '#geo-props-' + str(geo_id)
geo_node_derived = '#geo-derived-' + str(
geo_id) # node id for a derived feature
geo_node_derived_geom = '#geo-derived-geom-' + str(geo_id)
geo_node_derived_props = '#geo-derived-props-' + str(geo_id)
feature_events[geo_node] = []
geo_props = LastUpdatedOrderedDict()
geo_props['href'] = URImanagement.make_oc_uri(
uuid, item_type, self.cannonical_uris)
geo_props['type'] = geo.meta_type
if len(geo.note) > 0:
geo_props['note'] = geo.note
if uuid != geo.uuid:
geo_props['reference-type'] = 'inferred'
geo_props['reference-uri'] = URImanagement.make_oc_uri(
geo.uuid, 'subjects', self.cannonical_uris)
rel_meta = self.item_gen_cache.get_entity(geo.uuid)
if rel_meta is not False:
geo_props['reference-label'] = rel_meta.label
geo_props['reference-slug'] = rel_meta.slug
else:
geo_props['reference-label'] = self.manifest.label
geo_props['reference-type'] = 'specified'
if self.assertion_hashes:
geo_props['hash_id'] = geo.hash_id
geo_props['feature_id'] = geo.feature_id
if geo.specificity < 0 and self.manifest.item_type != 'projects':
# case where we've got reduced precision geospatial data
# geotile = quadtree.encode(geo.latitude, geo.longitude, abs(geo.specificity))
geo_props['location-precision'] = abs(geo.specificity)
geo_props[
'location-precision-note'] = 'Location data approximated as a security precaution.'
gmt = GlobalMercator()
geotile = gmt.lat_lon_to_quadtree(geo.latitude,
geo.longitude,
abs(geo.specificity))
tile_bounds = gmt.quadtree_to_lat_lon(geotile)
item_polygon = Polygon([[(tile_bounds[1], tile_bounds[0]),
(tile_bounds[1], tile_bounds[2]),
(tile_bounds[3], tile_bounds[2]),
(tile_bounds[3], tile_bounds[0]),
(tile_bounds[1], tile_bounds[0])]
])
item_f_poly = Feature(geometry=item_polygon)
item_f_poly.id = geo_node_derived
item_f_poly.geometry.id = geo_node_derived_geom
item_f_poly.properties.update(geo_props)
item_f_poly.properties['location-note'] = 'This region defines the '\
'approximate location for this item.'
item_f_poly.properties['id'] = geo_node_derived_props
features_dict[geo_node_derived] = item_f_poly
item_point = Point(
(float(geo.longitude), float(geo.latitude)))
item_f_point = Feature(geometry=item_point)
item_f_point.id = geo_node
item_f_point.geometry.id = geo_node_geom
item_f_point.properties.update(geo_props)
item_f_point.properties['location-note'] = 'This point defines the center of the '\
'region approximating the location for this item.'
item_f_point.properties['id'] = geo_node_props
features_dict[geo_node] = item_f_point
elif len(geo.coordinates) > 1:
# here we have geo_json expressed features and geometries to use
if geo.specificity < 0:
geo_props[
'location-precision-note'] = 'Location data approximated as a security precaution.'
elif geo.specificity > 0:
geo_props[
'location-precision-note'] = 'Location data has uncertainty.'
else:
geo_props['location-precision-note'] = 'Location data available with no '\
'intentional reduction in precision.'
item_point = Point(
(float(geo.longitude), float(geo.latitude)))
item_f_point = Feature(geometry=item_point)
item_f_point.properties.update(geo_props)
if uuid == geo.uuid:
#the item itself has the polygon as it's feature
item_db = Point(
(float(geo.longitude), float(geo.latitude)))
if geo.ftype == 'Polygon':
coord_obj = json.loads(geo.coordinates)
item_db = Polygon(coord_obj)
elif (geo.ftype == 'MultiPolygon'):
coord_obj = json.loads(geo.coordinates)
item_db = MultiPolygon(coord_obj)
elif (geo.ftype == 'MultiLineString'):
coord_obj = json.loads(geo.coordinates)
item_db = MultiLineString(coord_obj)
item_f_db = Feature(geometry=item_db)
item_f_db.id = geo_node
item_f_db.geometry.id = geo_node_geom
item_f_db.properties.update(geo_props)
item_f_db.properties['id'] = geo_node_props
features_dict[geo_node] = item_f_db
item_f_point.id = geo_node_derived
item_f_point.geometry.id = geo_node_derived_geom
item_f_point.properties['location-region-note'] = 'This point represents the center of the '\
'region defining the location of this item.'
item_f_point.properties['id'] = geo_node_derived_props
features_dict[geo_node_derived] = item_f_point
else:
#the item is contained within another item with a polygon or multipolygon feature
item_f_point.id = geo_node
item_f_point.geometry.id = geo_node_geom
item_f_point.properties['id'] = geo_node_props
item_f_point.properties['contained-in-region'] = True
item_f_point.properties['location-region-note'] = 'This point represents the center of the '\
'region containing this item.'
features_dict[geo_node] = item_f_point
else:
# case where the item only has a point for geo-spatial reference
geo_props[
'location-note'] = 'Location data available with no intentional reduction in precision.'
item_point = Point(
(float(geo.longitude), float(geo.latitude)))
item_f_point = Feature(geometry=item_point)
item_f_point.id = geo_node
item_f_point.geometry.id = geo_node_geom
item_f_point.properties.update(geo_props)
item_f_point.properties['id'] = geo_node_props
features_dict[geo_node] = item_f_point
if event_meta is not False:
# events provide chrological information, tied to geo features
# sometimes there are more than 1 time period for each geo feature
# in such cases, we duplicate geo features and add the different time event
# information to the new features
for event in event_meta:
rel_feature_num = 1 # default to the first geospatial feature for where the event happened
rel_feature_node = False
if event.feature_id > 0:
rel_feature_num = event.feature_id
if rel_feature_num >= 1:
rel_feature_node = '#geo-' + str(rel_feature_num)
act_event_obj = LastUpdatedOrderedDict()
act_event_obj = self.add_when_json(act_event_obj, uuid,
item_type, event)
if rel_feature_node is not False and feature_events is not False:
feature_events[rel_feature_node].append(act_event_obj)
if features_dict is not False:
if feature_events is not False:
for node_key, event_list in feature_events.items():
# update the feature with the first event "when" information
if len(event_list) > 0:
features_dict[node_key].update(event_list[0])
event_i = 1
for event in event_list:
if event_i <= 1:
# add the time info to the feature
old_feature = features_dict[node_key]
old_geo_id = old_feature.geometry['id']
old_prop_id = old_feature.properties['id']
features_dict[node_key].update(event)
else:
act_feature = copy.deepcopy(old_feature)
# now add new node ids for the new features created to for the event
new_node = node_key + '-event-' + str(
event_i)
act_feature.id = new_node
act_feature.geometry[
'id'] = old_geo_id + '-event-' + str(
event_i)
act_feature.properties[
'id'] = old_prop_id + '-event-' + str(
event_i)
act_feature.update(
event
) # add the time info to the new feature
features_dict[new_node] = act_feature
del (act_feature)
event_i += 1
feature_keys = list(features_dict.keys())
if len(feature_keys) < 1:
del features_dict[feature_keys[0]][
'id'] # remove the conflicting id
# only 1 feature, so item is not a feature collection
json_ld.update(features_dict[feature_keys[0]])
else:
feature_list = [
] # multiple features, so item has a feature collection
for node_key, feature in features_dict.items():
feature_list.append(feature)
item_fc = FeatureCollection(feature_list)
json_ld.update(item_fc)
return json_ld
