Add GeoJSON Area Calc (#19)

pyseed/seed_client.py

@@ -229,10 +229,11 @@ def get_buildings(self) -> List[dict]:
         return buildings
 
     def get_property_view(self, property_view_id: int) -> dict:
-        """Return a single property (view and state) by the property view id.
+        """Return a single property (view and state) by the property view id. It is
+        recommended to use the more verbose version of `get_property` below.
 
         Args:
-            property_view_id (int): ID of the property to return. This is the ID that is in the URL http://SEED_URL/app/#/properties/{property_view_id}
+            property_view_id (int): ID of the property to return. This is the ID that is in the URL http://SEED_URL/app/#/properties/{property_view_id} and resolves to {host}/api/v3/property_views/{property_view_id}
 
         Returns:
             dict: {
@@ -440,7 +441,7 @@ def update_labels_of_buildings(
         Args:
             add_label_names (list): list of label names to add, will be converted to IDs
             remove_label_names (list): list of label names to remove, will be converted to IDs
-            building_ids (list): list of building IDs to add/remove labels
+            building_ids (list): list of building IDs (property_view_id) to add/remove labels
             inventory_type (str, optional): taxlot or property inventory. Defaults to 'property'.
 
         Raises:

pyseed/utils.py

@@ -1,7 +1,104 @@
+# from __future__ import division
+
 # Imports from Third Party Modules
 import csv
+import json
+from math import pi, sin
 from pathlib import Path
 
+WGS84_RADIUS = 6378137
+
+
+def _rad(value):
+    return value * pi / 180
+
+
+def _ring_area(coordinates):
+    """
+    Calculate the approximate total_area of the polygon were it projected onto
+        the earth.  Note that this _area will be positive if ring is oriented
+        clockwise, otherwise it will be negative.
+
+    Reference:
+        Robert. G. Chamberlain and William H. Duquette, "Some Algorithms for
+        Polygons on a Sphere", JPL Publication 07-03, Jet Propulsion
+        Laboratory, Pasadena, CA, June 2007 http://trs-new.jpl.nasa.gov/dspace/handle/2014/40409
+
+    @Returns
+
+    {float} The approximate signed geodesic total_area of the polygon in square meters.
+    """
+
+    assert isinstance(coordinates, (list, tuple))
+
+    total_area = 0
+    coordinates_length = len(coordinates)
+
+    if coordinates_length > 2:
+        for i in range(0, coordinates_length):
+            if i == (coordinates_length - 2):
+                lower_index = coordinates_length - 2
+                middle_index = coordinates_length - 1
+                upper_index = 0
+            elif i == (coordinates_length - 1):
+                lower_index = coordinates_length - 1
+                middle_index = 0
+                upper_index = 1
+            else:
+                lower_index = i
+                middle_index = i + 1
+                upper_index = i + 2
+
+            p1 = coordinates[lower_index]
+            p2 = coordinates[middle_index]
+            p3 = coordinates[upper_index]
+
+            total_area += (_rad(p3[0]) - _rad(p1[0])) * sin(_rad(p2[1]))
+
+        total_area = total_area * WGS84_RADIUS * WGS84_RADIUS / 2
+
+    return total_area
+
+
+def _polygon_area(coordinates):
+
+    assert isinstance(coordinates, (list, tuple))
+
+    total_area = 0
+    if len(coordinates) > 0:
+        total_area += abs(_ring_area(coordinates[0]))
+
+        for i in range(1, len(coordinates)):
+            total_area -= abs(_ring_area(coordinates[i]))
+
+    return total_area
+
+
+def geojson_area(geometry):
+    """Calculate the area of a GeoJSON feature. This method is taken from
+    a combination of ChatGPT conversion of:
+    https://github.com/mapbox/geojson-area/blob/master/index.js
+    and
+    https://github.com/scisco/area/blob/master/area/__init__.py"""
+
+    if isinstance(geometry, str):
+        geometry = json.loads(geometry)
+
+    assert isinstance(geometry, dict)
+
+    total_area = 0
+
+    if geometry['type'] == 'Polygon':
+        return _polygon_area(geometry['coordinates'])
+    elif geometry['type'] == 'MultiPolygon':
+        for i in range(0, len(geometry['coordinates'])):
+            total_area += _polygon_area(geometry['coordinates'][i])
+    elif geometry['type'] == 'GeometryCollection':
+        for i in range(0, len(geometry['geometries'])):
+            total_area += geojson_area(geometry['geometries'][i])
+
+    return total_area
+
 
 def read_map_file(mapfile_path):
     """Read in the mapping file"""

tests/test_seed_client.py

@@ -103,11 +103,12 @@ def test_search_buildings(self):
         assert prop["state"]["address_line_1"] == "111 Street Lane, Chicago, IL"
         assert prop["state"]["extra_data"]["EUI Target"] == 120
 
-        # test the property view (same as previous, just less data)
+        # test the property view (same as previous, just less data). It
+        # is recommended to use `get_property` instead.
         prop = self.seed_client.get_property_view(properties[0]["id"])
+        print(prop)
         assert prop["id"] == properties[0]["id"]
-        assert prop["state"]["address_line_1"] == "111 Street Lane, Chicago, IL"
-        assert prop["state"]["extra_data"]["EUI Target"] == 120
+        assert prop["cycle"]["name"] == "pyseed-api-test"
 
         # There are 2 if filtering, because B-1 and B-10
         properties = self.seed_client.search_buildings(identifier_filter="B-1")