Grid search

1 files changed, 18 insertions, 3 deletions

diff --git a/store.py b/store.py
index 4af13ef..315b836 100644
--- a/store.py
+++ b/store.py
@@ -1,4 +1,5 @@
 from osm_parser import get_default_parser
+from collections import defaultdict
 
 
 class Node:
@@ -36,18 +37,32 @@ def extract_osm_nodes(f_name):
     global parser
     parser = get_default_parser(f_name)
     nodes = dict()
+    grid = defaultdict()
 
     for node in parser.iter_nodes():
-        nodes[node['id']] = Node(node['id'], node['lat'], node['lon'])
+        new_node = Node(node['id'], node['lat'], node['lon'])
+        nodes[node['id']] = new_node
 
     add_neighbours(nodes)
 
-    # remove nodes without neighbours
+    # remove nodes without neighbours.
     for node_id, node in nodes.copy().items():
         if not node.neighbours:
             del nodes[node_id]
 
-    return nodes
+    # create a "grid" by grouping nearby nodes.
+    for node in nodes.copy().values():
+
+        key = (int(round(node.lat, 3) * 1000), int(round(node.lng, 3)
+                                                   * 1000))
+
+        if key in grid.keys():
+            grid[key].append(node)
+
+        else:
+            grid[key] = [node]
+
+    return nodes, grid
 
 
 def select_nodes_in_rectangle(nodes, min_lat, max_lat, min_long, max_long):