[google-appengine] Re: how best to represent a directed graph w/ 25K nodes? (for path planning)

2008-12-29 Thread Ross Ridge
Amar Pai wrote: So if I shard my graph into 3 parts, my main class can store them as class variables and they'll persist across requests? That would be great. But will I run into quota problems holding 3M data in memory? (Assuming low overhead otherwise, and only 100ish requests per day)

[google-appengine] Re: how best to represent a directed graph w/ 25K nodes? (for path planning)

2008-12-28 Thread Amar Pai
There are 312 487 500 potential paths (25K choose 2) and edge weights are variable-- the cost function is determined by user-configurable multipliers. So precomputing all paths in advance isn't feasible, unless I'm misunderstanding what you mean. On Dec 27, 5:03 pm, David Symonds

[google-appengine] Re: how best to represent a directed graph w/ 25K nodes? (for path planning)

2008-12-28 Thread Amar Pai
So if I shard my graph into 3 parts, my main class can store them as class variables and they'll persist across requests? That would be great. But will I run into quota problems holding 3M data in memory? (Assuming low overhead otherwise, and only 100ish requests per day) Also, if I did it

[google-appengine] Re: how best to represent a directed graph w/ 25K nodes? (for path planning)

2008-12-27 Thread David Symonds
On Sat, Dec 27, 2008 at 5:16 AM, Amar Pai jcrue...@gmail.com wrote: I have a route planning webapp, written in Python, that uses Djikstra's algorithm to find the shortest path between two nodes in a directed graph. I want to port this to AppEngine, but I'm not sure how to represent the

[google-appengine] Re: how best to represent a directed graph w/ 25K nodes? (for path planning)

2008-12-27 Thread Robin B
Using Djikstra's shortest path algorithm, you can compute the shortest paths between all nodes in the same runtime as computing the path between any 2 nodes, so storing then querying the precomputed paths would be a good approach as mentioned above. Since there are no files in AppEngine, my