[R] Coloring counties on a full US map based on a certain criterion

[David L Carlson]

You can set the fg graphics parameter, for example

oldpar <- par(fg='white') # change the default fg (foreground color) to
white
map('county', 'iowa', fill=TRUE, col='light gray')
oldpar # reset fg to the default - black
map('state', 'iowa', lwd=3, add=TRUE)

Assuming you want the state outline in black with the county boundaries in
white. Otherwise just eliminate the last map command.

----------------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77843-4352


-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On
Behalf Of Dimitri Liakhovitski
Sent: Friday, January 13, 2012 2:14 PM
To: Sarah Goslee
Cc: r-help
Subject: Re: [R] Coloring counties on a full US map based on a certain
criterion

>
> But the help does say that additional arguments are passed to lines(),
> so you can use lty=0.
>
> That can leave white bits between counties if the areas don't line up
> precisely, so I think it looks better with the lines in black.

I agree, indeed it leaves white bits. Of course, I could try to change
the type of the lines using lty...
Sorry for one more question: can one change the color of these lines
(borders between counties) from black?
Thank you!
D.


>
> Sarah
>
>> Thank you!
>> Dimitri
>>
>> ### My criterion for all counties.:
>> allcounties<-data.frame(county=map('county', plot=FALSE)$names)
>>
allcounties$group<-c(rep(1:6,513),rep(1,4))[order(c(rep(1:6,513),rep(1,4)))]
>> ### My colors:
>> classcolors <- rainbow(6)
>> map('county',fill=TRUE,col=classcolors[allcounties$group])
>> map('state', lwd=2, add=TRUE)
>>
>>
>>
>>> Sure. Just start with
>>> map('county')
>>> instead.
>>> I like to add something like:
>>> map('state', lwd=3, add=TRUE)
>>
>> I am trying:
>> ### My criterion for all counties in the US:
>> allcounties<-data.frame(county=map('county', plot=FALSE)$names)
>> allcounties$group<-sample(1:5,3082,replace=TRUE)
>> ### My colors:
>> classcolors <- rainbow(5)
>> ### Trying to build the map - not working:
>>
map(database='usa',regions='county',fill=TRUE,col=classcolors[allcounties$gr
oup])
>>
>>
>>
>>> You'll need to instead coordinate with the names of the entire US:
>>>> length(map('county', plot=FALSE)$names)
>>> [1] 3082
>>>
>>> Sarah
>>>
> --
> Sarah Goslee
> http://www.functionaldiversity.org



-- 
Dimitri Liakhovitski
marketfusionanalytics.com

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