[R-sig-Geo] Coloring continents

[Hans-Jörg Bibiko]

On 23 Aug 2011, at 14:18, Etienne wrote:

> I believe there is an easy answer to my question, but I looked it up a bit
> and could not find anything. 
> I'm trying to have a simple world map (or better projection, if any) colored
> by continent. 
> One way to do that would be to enter a value for each country, but there is
> certainly an alternative to this time-costly & alienating solution, right?

Hi,

a very quick solution would be to use the data set "wrld_simpl" of package "maptools". Look at 

wrld_simpl at data

Here you find the column "REGION".


Then you can do the following:

library(maptools)
data(wrld_simpl)
my_cols <- c()
my_cols[20]  <- "red"
my_cols[3]  <- "green"
my_cols[143]  <- "blue"
my_cols[151]  <- "yellow"
my_cols[10]  <- "brown"
my_cols[1]  <- "white"
plot(wrld_simpl, col=my_cols[wrld_simpl at data$REGION+1])


Note: +1 is here necessary to catch the region "0"

The only problem is Russia since it belongs to Europe and Asia.

Cheers,

--Hans



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Hans-Joerg Bibiko
Max Planck Institute for Evolutionary Anthropology
Department of Linguistics
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