Hello all, Working on mapping some probabilities using R to a geographic unit called a TAZ. The below data will work but you will have to set your directory for the shape file. Never did this before so hopefully this works. ResProbs is just supposed to be a value between 0-1, sorry if that more complicated than it needed to be. TazFile <- "*directory*/TAZ.shp" TazShape <- readShapeSpatial(TazFile) TazShape<-TazShape[order(TazShape$TAZ_NUM),] ResTaz<-25:666 ResProbs<-rnorm(642,0:1) ResProbs[ResProbs>1]=.5 ResProbs[ResProbs<-1]=.2 ResProbs<-abs(ResProbs) ResProbs..<-data.frame(ResTaz,ResProbs) names(ResProbs..)<-c("Taz","SFsubM") TazShape$SFsubM<-ResProbs..$SFsubM[match(TazShape$TAZ_NUM,ResProbs..$Taz)] brks<-cut(TazShape$SFsubM, breaks=c(seq(0,1, by=0.1), Inf) , right=TRUE,include.lowest=TRUE) cols <- grey((length(brks):2)/length(brks)) plot(TazShape, col=cols[findInterval(TazShape$SFsubM, brks, all.inside=TRUE)]) I get the error: Error in findInterval(TazShape$SFsubM, brks, all.inside = TRUE) : 'vec' must be sorted non-decreasingly The code i took this from created "brks" as a quantile returning: 0% 10% 20% 30% 40% 50% 60% 0.00000000 0.03858501 0.07693546 0.11647164 0.14702968 0.18308665 0.22484961 70% 80% 90% 100% 0.26566555 0.31217598 0.39463130 0.73439360 which is not what i want but rather putting data into the correct "bins". I remedied this by the above code describing "brks", which now returns an interval. So basically what im after is to illustrate probabilities for each of my geographic units for my shape file with breaks at each .1, using gray or any other color for that matter. Thanks http://n4.nabble.com/file/n1679914/TAZ.shp TAZ.shp -- View this message in context: http://n4.nabble.com/Getting-choropleth-map-intervals-correct-tp1679914p1679914.html Sent from the R help mailing list archive at Nabble.com.