This is a common problem in GIS. I'd suggest doing a simple check for whether each point is within a simple lat/lon box - that should be fast enough with only 400 points, and should narrow down the list enough to be able to check the distance on just those few.
If you're doing this a lot, put the data in SQLite with indexes on lat & lon; that way you can do this initial "box" query easily & efficiently. String Martijn van der Plaat wrote: > Dear all, > > In my application I have a list of +400 GPS coordinates which I > retrieve from addresses. The application should give me the top X > nearest coordinates based on my current location. > > This application is possible (I think) with the distanceBetween > function. But (I think) the application is really inefficient when i > iterate through the list of 400 coordinates and check the distance > within a certain time interval. > Another option is (I think) the proximityAlert function? All > coordinates are loaded in this function and when my current location > comes in the radius of a coordinate an alert is given. But the > downside of this solution (I think) is the high memory usage which > implies a short battery life of the Android phone? > > Please can anybody help me to make the right decision? > > Greets, > Martijn --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~----------~----~----~----~------~----~------~--~---
