make separate geom handling optional

examples/using_geopandas.py

@@ -47,7 +47,9 @@
 coords = points_to_coords(south_am_cities.geometry)
 
 # calculate the regions
-poly_shapes, poly_to_pt_assignments = voronoi_regions_from_coords(coords, south_am_shape)
+# we set "per_geom=False" so that the whole continent is treated as one area and Voronoi regions
+# span over to Tierra del Fuego
+poly_shapes, poly_to_pt_assignments = voronoi_regions_from_coords(coords, south_am_shape, per_geom=False)
 
 
 #%%

geovoronoi/_voronoi.py

@@ -32,7 +32,7 @@ def points_to_coords(pts):
  return np.array([p.coords[0] for p in pts])
 
 
-def voronoi_regions_from_coords(coords, geo_shape):
+def voronoi_regions_from_coords(coords, geo_shape, per_geom=True):
  """
  Calculate Voronoi regions from NumPy array of 2D coordinates `coord` that lie within a shape `geo_shape`. Setting
  `shapes_from_diff_with_min_area` fixes rare errors where the Voronoi shapes do not fully cover `geo_shape`. Set this
@@ -57,20 +57,21 @@ def voronoi_regions_from_coords(coords, geo_shape):
  doesn't intersect with `geo_shape`.
  """
 
- logger.info('running Voronoi tesselation for %d points' % len(coords))
+ logger.info('running Voronoi tesselation for %d points / treating geoms separately: %s' % (len(coords), per_geom))
 
  if isinstance(coords, np.ndarray):
  pts = coords_to_points(coords)
  else:
  pts = coords
  coords = points_to_coords(pts)
 
- if isinstance(geo_shape, Polygon):
+ if not isinstance(geo_shape, (Polygon, MultiPolygon)):
+ raise ValueError('`geo_shape` must be a Polygon or MultiPolygon')
+
+ if not per_geom or isinstance(geo_shape, Polygon):
  geoms = [geo_shape]
- elif isinstance(geo_shape, MultiPolygon):
+ else: # Multipolygon
  geoms = geo_shape.geoms
- else:
- raise ValueError('`geo_shape` must be a Polygon or MultiPolygon')
 
  pts_indices = set(range(len(pts)))
  region_polys = {}