confused and in need of a tea break

[pmjf1977]

Hi all, and thanks for reading my post:

I have a list of locations with latitude and longitude points defined. I have a list of geographical regions and I need to assign a geographical region based on the lat/long data.

Within the regions there are sub regions... for example region of "London" has an "inner london" and "outer London" region both are also within the region headline of "UK"

how do I assign location to the lowest geographical detail level?

any help or ideas welcome.....I do not want to revert to the manual process of looking on a map as there are hundreds of locations to assign.


thanks all.

 

[yogeshmaney]

Chief, If you descript the requirement, will be very helpful. provide snapshot or data sample

 

[John_w]

Google/search this forum for reverse geocoding.

 

[Ruddles]

It sounds as though your database needs to have a field in it which flags whether each region is further sub-divided or whether it's the smallest geographical subdivision. Your matching algorithm would then only need to look at regions which aren't subdivided any further.

Presumably these regions are irregular in shape? How are their boundaries defined? I mean, are they rectangular, so we just need to work out whether the location's lat/long falls inside the lat/long of the region, and that means the location must be in that region?

 

[pmjf1977]

thanks guys, I will try the reverse geocode work, if I get no joy there I will seek approval to post a data extract to the site.

cheers.

 

[pmjf1977]

Ruddles, the regions are irregular in shape. the sub regions are more regular as these are not linked to any geo/political areas of extent.

to flesh out the issue without waiting for the beurocratical process of approval through our internal (or infernal) process....
there are 5 key regions or countries with irregular borders. These have been squared off to simplify the issue where there is low risk of cross border locations. Any where the risks are high can be picked out prior to cutting the data and dealt with manually.

within 3 of the regions there are sub regions. These are generally capital cities with high concentration of locations. London is the only one that is further subdivided (as a square within a square)