R help - Feb 2009 - creating a map

I'm trying to create a fairly basic map using R. What i want to get is the
map of the country with circles representing a count of students in each
state.
What I've done so far is as following -
  map("state")
 symbols(data1$count,circles=log(data1$count)*3,fg=col,bg=col,add=T,inches=F)

this gives me the map of the country, but one that's not populated by my
counts.
Does anyone know what I'm doing wrong?

Also, if anyone can recommend a good reference for creating maps in R, I'd
really appreciate that.

thank you

	[[alternative HTML version deleted]]

Two places that have worked examples leap to mind:

--- Sarkar's online accompaniment to his book:
http://lmdvr.r-forge.r-project.org/figures/figures.html
Thumbing through the hard copy I see Figure 6.5 might of interest.

--- Addicted to R's graphics gallery:
http://addictedtor.free.fr/graphiques/search.php?q=map&engine=RGG

--  
David Winsemius

On Feb 17, 2009, at 11:53 AM, Alina Sheyman wrote:
> I'm trying to create a fairly basic map using R. What i want to get  
> is the
> map of the country with circles representing a count of students in  
> each
> state.
> What I've done so far is as following -
>  map("state")
> symbols 
> (data1$count,circles=log(data1$count)*3,fg=col,bg=col,add=T,inches=F)
>
> this gives me the map of the country, but one that's not populated  
> by my
> counts.
> Does anyone know what I'm doing wrong?
>
> Also, if anyone can recommend a good reference for creating maps in  
> R, I'd
> really appreciate that.
>
> thank you
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

You need to give the symbols function the locations where you want the centers
of the circles to be.  Some datesets with map information also have centers of
the states that you can use, for the USA, there is the state.center dataset that
may work for you, or the maptools package function get.Pcent will compute a
center for polygons (there are probably other similar functions in other
packages).

For adding circles to a map of the USA, you may want to look at the state.vbm
data in the TeachingDemos package (works with maptools package), but you will
need to computer the centers of the polygons, they don't match state.center
or others.

Hope this helps,

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Alina Sheyman
> Sent: Tuesday, February 17, 2009 9:53 AM
> To: r-help at r-project.org
> Subject: [R] creating a map
> 
> I'm trying to create a fairly basic map using R. What i want to get is
> the
> map of the country with circles representing a count of students in
> each
> state.
> What I've done so far is as following -
>   map("state")
> 
> symbols(data1$count,circles=log(data1$count)*3,fg=col,bg=col,add=T,inch
> es=F)
> 
> this gives me the map of the country, but one that's not populated by
> my
> counts.
> Does anyone know what I'm doing wrong?
> 
> Also, if anyone can recommend a good reference for creating maps in R,
> I'd
> really appreciate that.
> 
> thank you
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.