Added function get_relative_area_range and its test

GDE_TOOLS_create_industrial_cells.py

@@ -1175,3 +1175,31 @@ def get_distance_centroids(cells_gdf, col_lon, col_lat):
     max_dist = np.array(dist).max()
 
     return max_dist
+
+
+def get_relative_area_range(cells_gdf):
+    """This function calculates a measure of the variability of the area of the geometries
+    contained in cells_gdf, by subtracting the minimum area value from the maximum one and
+    normalising it by the mean.
+
+    Args:
+        cells_gdf (GeoDataFrame): GeoPandas GeoDataFrame with at least a geometry
+                                  column.
+
+    Returns:
+        areas_range_relative (float): [max(areas) - min(areas)] / mean(areas), where
+                                      areas is the area of the polygons in the geometry
+                                      column of cells_gdf.
+    """
+
+    # Check that in_gdf has the needed columns and terminate otherwise:
+    if "geometry" not in cells_gdf.columns:
+        print("ERROR!! geometry missing as column of cells_gdf")
+        return np.inf
+
+    areas = [geom.area for geom in cells_gdf["geometry"].values]
+    areas = np.array(areas)
+    areas_range = areas.max() - areas.min()
+    areas_range_relative = areas_range / areas.mean()
+
+    return areas_range_relative

tests/test_GDE_TOOLS_create_industrial_cells.py

@@ -1262,3 +1262,32 @@ def test_get_distance_centroids():
     function_out = gdet_cr_ind.get_distance_centroids(dummy_gdf, "LONGITUDE", "LATITUDE")
 
     assert np.isinf(function_out)
+
+
+def test_get_relative_area_range():
+    """
+    The original function is very simple. The test case is built within this test function.
+
+    """
+    # Build a GeoPandas DataFrame for testing:
+    d = {
+        "geometry": [
+            Polygon([(22.0, 37.8), (23.5, 37.8), (23.5, 38.8), (22.0, 38.8)]),
+            Polygon([(-18.0, 36.8), (-17.0, 36.8), (-17.0, 38.8), (-18.0, 38.8)]),
+            Polygon([(22.5, -41.8), (23.5, -41.8), (23.5, -40.9), (22.5, -40.9)]),
+            Polygon([(-18.5, -41.9), (-16.5, -41.9), (-16.5, -40.9), (-18.5, -40.9)]),
+        ]
+    }  # Areas are: 1.5, 2.0, 0.9, 2.0
+    dummy_gdf = gpd.GeoDataFrame(d)
+
+    # Call function to test:
+    function_out = gdet_cr_ind.get_relative_area_range(dummy_gdf)
+
+    assert "{:.4f}".format(function_out) == "0.6875"
+
+    # Rename the columns and test again that the output is inf if there is no geometry column
+    # int he input GeoDataFrame:
+    dummy_gdf = dummy_gdf.rename(columns={"geometry": "geom"})
+    function_out = gdet_cr_ind.get_relative_area_range(dummy_gdf)
+
+    assert np.isinf(function_out)