Merge pull request #132 from toruseo/develop

add `get_shortest_path_distance_between_all_nodes`

uxsim/uxsim.py

@@ -2208,6 +2208,38 @@ def get_nodes_in_area(W, x, y, r):
             if (node.x-x)**2 + (node.y-y)**2 < r**2:
                 nodes.append(node)
         return nodes
+
+    def get_shortest_path_distance_between_all_nodes(W, return_matrix=False):
+        """
+        Get the shortest distances (in meters) between all node pairs based on link lengths.
+
+        Parameters
+        ----------
+        return_matrix : bool, optional
+            Whether to return the distance matrix as a numpy array. Default is False.
+
+        Returns
+        -------
+        dict or numpy array
+            Returns a dictionary of distances between nodes whose key is node if `return_matrix` is False.
+            Returns a numpy array of distances between nodes whose index is node.id if `return_matrix` is True.
+        """
+        num_nodes = len(W.NODES)
+        distances = np.full((num_nodes, num_nodes), np.inf)  # Initialize with infinity
+
+        # Fill in the distances based on the link lengths
+        for link in W.LINKS:
+            i = link.start_node.id
+            j = link.end_node.id
+            distances[i, j] = min(distances[i, j], link.length)
+
+        # Use Dijkstra algorithm to compute shortest distances
+        distances = *dijkstra(csr_matrix(distances), directed=True, return_predecessors=False),
+
+        if return_matrix == True:
+            return distances
+        else:
+            raise NotImplementedError("return_matrix=True is not implemented yet.")#TODO
 
     def load_scenario_from_csv(W, fname_node, fname_link, fname_demand, tmax=None):
         """