Removed calculate_district_area

exposurejapan/database.py

@@ -1026,41 +1026,6 @@ class JapanDatabase(SpatialiteDatabase):
 
         return polygon.area
 
-    def calculate_district_area(self):
-        """
-        Selects all districts (i.e. administrative units) and their geometry from District
-        table and calculates the unit area for each district and stores it in a list.
-
-        Returns:
-            list:
-                List with districts, their geometries and their unit areas.
-        """
-
-        # Select the district_id and geometry from District table
-        sql_statement = "SELECT id, AsWKT(CastAutomagic(geom)) FROM District"
-        self.cursor.execute(sql_statement)
-
-        # Create an empty list to store the districts and their unit areas
-        districts = []
-
-        # Store all districts and their geometry in a list
-        for row in self.cursor:
-            add_element_and_get_index(row, districts)
-
-        # Calculate the district area and add it to the districts list.
-        for row in districts:
-            admin_unit_geom = shapely.wkt.loads(row[1])
-            administrative_unit_area = (
-                self.albers_area_calculation(admin_unit_geom, "epsg: %d")
-                % constants.JGD2000
-                * 0.000001
-            )  #
-            # Convert to square kilometers
-            index = districts.index(row)
-            districts[index] = row + (administrative_unit_area,)
-            numpy.seterr(divide="ignore", invalid="ignore")
-        return districts
-
     def import_population_distribution(self, population_distribution_filepath):
         """
         Imports all population data from the 2015 Population Census file provided
@@ -1167,8 +1132,12 @@ class JapanDatabase(SpatialiteDatabase):
             "6_150m2 and over",
         ]
 
+        # Select the district_id and area_size from District table
+        sql_statement = "SELECT id, area_size FROM District"
+        self.cursor.execute(sql_statement)
+
         # Store all district (i.e. administrative unit) areas with their district_ids in a list
-        districts = self.calculate_district_area()
+        districts = self.cursor.fetchall()
 
         # Import population data into the database
         self.import_population_distribution(population_distribution_filepath)