On Sep 2, 2:57 pm, marcelo <[EMAIL PROTECTED]> wrote: > > I think this is what I remembered about inaccuracies: > > From:http://www.census.gov/geo/www/cob/shape_info.html > > "Please note: The first four fields - Area, Perimeter, > xxnn_d00_, xxnn_d00_I are produced as a by-product of > the cartographic boundary file creation process, and > have no meaning for public data users, therefore, > ignore or delete these fields."
When I look at the actual contents of the Area column referenced there (in a downloaded sample shapefile), the value is a small decimal fraction that is not remotely close the number your site reports as square miles. (I can't even tell what the units are supposed to be in the Census Area column.) So somewhere along the line, someone may have done some conversion math. The actual polygons in the shapefile, when measured empirically by my GIS program (I use Manifold) correspond quite closely to the numbers reported on Wikipedia and attributed to Census as the total area for each county. And the Census American Fact Finder site reports the same numbers. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" 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/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
