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I want to ask about what different of function : "astar_sp" and "shortest_path_astar" ?

Do you think the query's result from both of them is same or different?

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shortest_path_astar is a the basic function for the a-star algorithm. Other functions like astar_sp are wrapper functions that often simplify but also extend input parameters and further process the shortest path result, usually based on certain assumptions:

You can create your own wrapper functions by modifying existing ones. But they all base on shortest_path_astar.

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I see. Ok. Thankyou very much..:) I like ur answer mr.dkastl..:) – robi_blitzx Jun 5 '12 at 2:56
Well, it's probably a good idea to then mark the question as "solved". – dkastl Jun 5 '12 at 9:45
oia, i forgot to ask, the result is same, right ? – robi_blitzx Jun 6 '12 at 0:16
The path is the same, but the format of the result will be different. – dkastl Jun 6 '12 at 19:20
hmm, i have try both of them.. and result is : 1. the path is different. 2. the result of length(it's cost, right?) is different when i used length(The_geom) function.. do you know why? – robi_blitzx Jun 7 '12 at 1:35

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