counties in different colours using map()
Tord Sn?ll wrote:
Hi,
I would like to plot a map of US counties using different colors. map()
seems to be the function to use, e.g.
library(maps); map('usa'); map('county', 'colorado', add=T,fill = T,
col=c(1:5))
plots Colorado counties using colours 1 to 5.
However, I want each color to represent a certain value - a value to be
picked from a data frame.
This code should show a correspoding map at the level of states:
state.names <- system('tr "[A-Z]" "[a-z]"', state.name)
map.states <- unix('sed "s/:.*//"', map(names=T,plot=F))
state.to.map <- match(map.states, state.names)
color<- votes.repub[state.to.map, votes.year = 1900] / 100
map('state', fill=T, col=color); map('state', add=T)
Hi Tord,
I don't know if this matches the color to the state as I couldn't get
your "unix" function to work, but it does what I think you want.
library(maps)
map("usa")
data(votes.repub)
library(plotrix)
state.col<-color.scale(votes.repub[,30],c(0,1),0,c(1,0))
map("state",fill=TRUE,col=state.col)
Jim