Tord Snäll 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 ______________________________________________ R-help@stat.math.ethz.ch 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.