pysal.explore.spaghetti.dijkstra_mp¶

pysal.explore.spaghetti.dijkstra_mp(ntw_cost_node)[source]¶

Compute the shortest path between a start node and all other nodes in the web utilizing multiple cores upon request.

Parameters:	ntw_cost_node : tuple tuple of arguments to pass into dijkstra (1) ntw - spaghetti.Network; spaghetti Network object; (2) cost - dict; key is tuple (start node, end node); value is float - Cost per edge to travel, e.g. distance; (3) node - int; Start node ID
Returns:	distance : list List of distances from node to all other nodes. pred : list List of preceeding nodes for traversal route.

Notes

Based on [Dij59].

Examples

>>> import pysal.explore.spaghetti as spgh
>>> from pysal.lib import examples
>>> ntw = spgh.Network(examples.get_path('streets.shp'))
>>> distance, pred = spgh.util.dijkstra(ntw, ntw.edge_lengths, 0)
>>> round(distance[196], 4)
5505.6682
>>> pred[196]
133