GIS 点之间的行驶距离

Question

I have a large number of GIS (latitude, longitude) coordinates, and I'd like to get the distance between them. Is there a service that will calculate the shortest path for me? I know about google maps, but I'd like something I can use from Python, and that can handle a large batch of requests at once.

I'm looking for the driving distance, so a straight distance won't do.

Thanks

Answer 1

So I take it based on your question and the answers posted that you are asking what program to use? If you can find a way to get a copy for free or cheap (like through work, school, etc) I'd recommend ArcGIS 9.x. It has its quirks, but it's highly supported by the user community and there are a lot of forums and help/training books available for it. Also, they have adopted Python as their official scripting language for the program (Sweeeet!).

Another option that is less expensive is GRASS. It's a free, open-source, well established, powerful and multiplatform GIS program. It might have a bit steeper learning-curve than ArcGIS, but I've heard very good things about it considering it's a free program.

This website lists info on free, open-source (FOS) GIS programs http://opensourcegis.org/ and could give you some good info on your other choices.

I couldn't tell if you were asking a question about how to measure the distance between two points and finding shortest travel distances in a GIS program or if you were just mentioning that's the kind of stuff you would need to do. Either way, ArcGIS is well suited for those tasks. Some of the tools in ArcGIS's ArcToolbox already have commands to help you find optimal transportation routes. This link lets you explore some of the tools available ArcToolbox Help . Most of the tools in ArcToolbox have a GUI batch processing option automatically included as well. Measuring point to point distances on an individual basis is easy in ArcGIS, and if you needed to measure a bunch of point to point pairs, you could write a quick Python script to easily do it for you.

I think I've answered all of your questions. Feel free to let me know if there is something I missed or that doesn't make sense. Hope this helps, buddy.

Answer 2

Check out OpenStreetMap. You can download their map data and have it lying around on your local system. http://wiki.openstreetmap.org/wiki/Routing discusses the various routing systems for their data.

You are aware that the traveling salesman problem is np-complete?

Answer 3

using Qgis :

• Use the delimited text plugin to import the data
• save the import as a shape file
• Open the shape file
• using the ftools plugin, calculate the matrix distance

Answer 4

If you have interconnections between the points you could use Dijkstra's algorithm for a 'shortest path from a single point' or Floyd's algorithm for an 'all pairs' shortest path computation.

Neither are particularly complicated, however they do assume you know the lengths of the roads between the points. You will need to have this data to compute a driving distance.