You can get U.S. state and county boundary data files from various places. Here are a few. The most common GIS data format is called a "ESRI shapefile" which has been around for about 15 years or so. There are plenty of packages out there that can read/convert shapefiles. (For command line, programmatic use, check out GDAL.OGR, http://www.gdal.org/ogr/)
/The National Map/ Seamless Server http://seamless.usgs.gov/index.php (if you can figure out how to use it!) The National Atlas http://www-atlas.usgs.gov/atlasftp.html U.S. Census Bureau TIGER files http://www2.census.gov/cgi-bin/shapefiles/national-files U.S. Census Bureau Generalized boundaries (smaller file sizes, less accuracy) http://www.census.gov/geo/www/cob/bdy_files.html Geospatial One Stop (large repository of US GIS data and map services) http://gos2.geodata.gov/ Note that there are tons of vertices with state or county level data. There are about 3100+ counties. I've seen Google Maps struggle (polygon overlays) with only hundreds of polygons at lesser resolution. So, KML or straight coordinates wouldn't help much here. However, a flash widget or served from a map server would be fine. - John David Huynh wrote: > John Callahan wrote: > >> Regarding the last point, I agree that it's difficult to see which >> direction to go. >> > Yes,... other people have used some of the tools for showing clinical > drug trial data, rocket test data, educational materials, historical > events, software development project deliverables, ... > > >> There are so many ways to store geospatial, many of which are resource >> and storage hogs. Imagine having 100 items, each with a URL-style >> field pointing to WMS services and Image and KML overlays to be >> displayed on the same map. Performance would definitely be >> sacrificed. Technically, this doesn't seem to be very hard as Google >> Maps supports these natively. Even if you integrated OpenLayers (or >> similar FOSS Geo map clients), these types of overlays can be easily >> done. Performance and variety of standards jump out at me as the >> biggest obstacles. >> >> On a separate note, what about having a map extension that is similar >> to Timeplot? For example, you can bring in one CSV file or >> spreadsheet that contains dozens or hundreds of data points w. >> location. It could be a 2D array for different types of markers (like >> separate lines on Timeplot) or maybe separate maps (like different >> bands in Timeline.) >> > That would be a good way to go. You will also probably want Babel to be > able to convert KML files from another domain into Exhibit JSONP. Note > that Timeplot can only load files (except for JSONP) from the same web > domain. > > By the way, one of the type of geospatial data that I think will be very > useful is state and county boundaries, starting with those of the U.S. > For example, > http://elections.nytimes.com/2008/results/president/map.html > (switch to "County leaders") is quite an interesting visualization, and > the NY Times has produced a lot of U.S. maps broken down into counties. > If you click on a state on that map, it zooms in and you can then select > each county. I think that kind of map should become a reusable widget, > for anyone to plot any sort of per county data. Do you know where to > obtain the boundaries for the counties and states? > > David > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "SIMILE Widgets" 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/simile-widgets?hl=en -~----------~----~----~----~------~----~------~--~---
