Warning
This documents an unmaintained version of NetworkX. Please upgrade to a maintained version and see the current NetworkX documentation.
astar_path¶
- astar_path(G, source, target, heuristic=None, weight='weight')[source]¶
Return a list of nodes in a shortest path between source and target using the A* (“A-star”) algorithm.
There may be more than one shortest path. This returns only one.
Parameters : G : NetworkX graph
source : node
Starting node for path
target : node
Ending node for path
heuristic : function
A function to evaluate the estimate of the distance from the a node to the target. The function takes two nodes arguments and must return a number.
weight: string, optional (default=’weight’)
Edge data key corresponding to the edge weight.
Raises : NetworkXNoPath
If no path exists between source and target.
See also
shortest_path, dijkstra_path
Examples
>>> G=nx.path_graph(5) >>> print(nx.astar_path(G,0,4)) [0, 1, 2, 3, 4] >>> G=nx.grid_graph(dim=[3,3]) # nodes are two-tuples (x,y) >>> def dist(a, b): ... (x1, y1) = a ... (x2, y2) = b ... return ((x1 - x2) ** 2 + (y1 - y2) ** 2) ** 0.5 >>> print(nx.astar_path(G,(0,0),(2,2),dist)) [(0, 0), (0, 1), (1, 1), (1, 2), (2, 2)]