This might of helpful — I made this a while ago,
http://sites.google.com/site/malecki/map-notes

I have done cdist maps one or two times, but you just have to get your data
merged onto the SpatialPolygonsDataFrame , which is exactly what Santiago
does.
Good luck!

Michael Malecki

On Thu, Feb 2, 2012 at 1:30 AM, Santiago Olivella <[log in to unmask]>wrote:

> Hello Scott,
>
> if I understood you correctly, what you want to do can be done simply.
> You'll need the `sp' and `maptools' packages for R (and the census
> shapefiles; I used the 2010 TIGER files). The code at http://bit.ly/z2cS7Wshould do the rest. I apologize for not having real data in the example.
> After the data is clean, really all it takes is one line of code.
>
> I hope this helps. Apologies if this is redundant information.
>
> Best,
>
> SO
> -----------------------
> Santiago Olivella
> Ph.D. Program in Political Science
> Washington University in St. Louis
> http://solivella.wustl.edu
>
>
>
>
>
> On Feb 1, 2012, at 3:26 PM, Scott Moser wrote:
>
> > Dear All,
> >
> > Are there 'easy' ways to display congressional-district level
> > information in a map, perhaps in R: ?  For example, lets say I wanted
> > to plot a map of the US, along with all congressional districts.  This
> > can be by, for example, getting the shape files for the 100th congress
> > from census.gov and plotting them in R. (though, the resulting map is
> > quite ugly).  Lets say I wanted to color each district by the percent
> > republican vote in the 2008 pres. election.  Is there a convenient way
> > to do this?  The answer seems to be 'yes' if one wants to color
> > state, or even counties, but I was having some trouble with cong.
> > districts.
> >
> > Any pointers would be much appreciated.
> >
> > Thanks,
> >
> > Scott
> >
> >
> > Assistant Professor
> > Department of Government
> > University of Texas at Austin
> > 1 University Station A1800
> > Austin, TX 78712
> >
> > 512-232-7305 (Office)
> >
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