Encoded Zip Code Polygons:
Plot the boundary area of any US zip code on to the map as a polygon. John shares the following: ..This one is especially cool in that it uses a Douglas-Peucker algorithm to compute the levels part of the encoding scheme that we wrote in Perl:
http://www.usnaviguide.com/google-encode.htm (open source Perl module)
Douglas-Peucker algorithm:
http://www.usnaviguide.com/douglas-peucker.htm (open source Perl module)
NPA Boundary Map (telephone area codes):
John describes this map tool: "..This one is very useful to anyone looking to see how an area code is layed out in the real world. The data should be fairly accurate. Either click on the map or key in an area code. It can also be accessed directly by including a parameter: http://www.usnaviguide.com/areacode.htm?n=607 (replace "607" with your area code)
See the rest of John's great (and very useful) Google Maps tools here..
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3 comments:
I just noticed that suddenly the area code map's link redirects to the zip code version! What's with that?? I want to see the area code version again!
Posting on behalf of John Coryat (the above map tool creator):
In order to create such a map, you'd need an accurate database of zip codes. The voting districts are available for free from the Census, but since these districts are quite dynamic, finding actual accurate polygons is going to be difficult. The Census Cartography Boundary data web site is an excellent place to start though. Search Google for this term to locate.
I also suggest taking a look at a workshop I gave back in February that describes how to create custom maps like you are looking for, search Google for "coryat Google youtube" to locate that presentation. Source code for all examples is available for download.
You really know your stuff... Keep up the good work!
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