Check out http://www2.census.gov/cgi-bin/shapefiles2009/national-files - left hand side has national - level data.
All 5 digit zipcode files are based on 2002 data but zipcode boundaries change less frequently than tracts and blockgroups, there may be some issues in correctly mapping out areas in high growth regions of the U.S. with new zipcodes. Sharon On Fri, Aug 20, 2010 at 12:47 PM, Michael Haenlein <haenl...@escpeurope.eu>wrote: > Thanks very much for your reply, Roger! > > I have downloaded the shape files from the US Census ZCTA webpage. In case > anyone else is interested in obtaining them the URL is: > http://www.census.gov/geo/www/cob/z52000.html#shp > > I also managed to import those files into R and to convert them into > a neighbour list: > > Alabama <-readShapePoly("c:/111/zt01_d00") > Alaska <-readShapePoly("c:/111/zt02_d00") > Arizona <-readShapePoly("c:/111/zt04_d00") > ... > > Alabama.nb <- poly2nb(Alabama) > Alaska.nb <- poly2nb(Alaska) > Arizona.nb <- poly2nb(Arizona) > ... > > The problem is that instead of having one neighbour list I now have 52 ones > (one for each state). > Is there a way to combine all of them into one large neighbour list which I > can then use as an input for my analysis? > > > > > -----Original Message----- > From: Roger Bivand [mailto:roger.biv...@nhh.no] > Sent: Thursday, August 19, 2010 23:54 > To: Michael Haenlein > Cc: r-sig-geo@stat.math.ethz.ch > Subject: Re: [R-sig-Geo] Moran's I based on ZIP Code data > > On Thu, 19 Aug 2010, Michael Haenlein wrote: > > The first thing is to get the locations of the zip codes (about 30,000?) - > they are published as shapefiles by state (US Census ZCTA), so a polygon > representation is possible, but you could also look for a point > representation. Next make a neighbour list (nb) object to the zip code > entities for which you have observations. Then you could use nb2blocknb() > in > spdep to "block up" observations where more than one belongs to the same > zip > code, which effectively makes all the observations in a zip code > neighbours, > and adds all the observations in neighbouring zip codes too. > It was written for housing data with only a postcode but no geocoded > address. > > Hope this helps, > > Roger > > > -- > Roger Bivand > Economic Geography Section, Department of Economics, Norwegian School of > Economics and Business Administration, Helleveien 30, N-5045 Bergen, > Norway. > voice: +47 55 95 93 55; fax +47 55 95 95 43 > e-mail: roger.biv...@nhh.no > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
