Hi: time <- c(1, 2, 3, 7,10,11,14,16,20) pressure <- c(0,10,20,20,50,18,60,65,90) status <- c(0, 0, 1, 1, 1, 0, 3, 3, 3)
# You want to combine the vectors into a data frame instead # of concatenating them into one long vector. df <- data.frame(time, pressure, status) df time pressure status 1 1 0 0 2 2 10 0 3 3 20 1 4 7 20 1 5 10 50 1 6 11 18 0 7 14 60 3 8 16 65 3 9 20 90 3 library(lattice) mycols <- c('green', 'orange', 'red') xyplot(pressure ~ time, data = df, group = status, type = 'b', col = mycols) For this type of graphic, the lattice package works well. The package has its own book and extensive help pages. On Thu, Sep 23, 2010 at 4:38 AM, Richard DeVenezia <rdevene...@gmail.com>wrote: > New to R. I am trying to create a simple xy plot wherein the line > segment color is determined by a categorical column > > The following does not change colors for me, probably because I don't > quite have a handle on either functions or value mapping syntax. > ---------- > time <- c(1, 2, 3, 7,10,11,14,16,20) > pressure <- c(0,10,20,20,50,18,60,65,90) > status <- c(0, 0, 1, 1, 1, 0, 3, 3, 3) > measures <- c(time,pressure,status) > > # A bad idea. Don't use attach(); use the function with(dataframe, expression) instead; see ?with > attach(measures) > > statusColor <- function (x) { > if (x==0) return ("green") > if (x==1) return ("orange") > if (x==2) return ("pink") > if (x==3) return ("red") > } > > par(mfrow=c(3,2)) > plot(time,pressure,type="l") > plot(time,pressure,type="l") > plot(time,pressure,type="l") > plot(time,pressure,type="l") > plot(time,pressure,type="l",col=statusColor(status)) > plot(time,pressure,type="l") > ---------- > Warning message: > In if (x == 0) return("green") : > the condition has length > 1 and only the first element will be used > > > HTH, Dennis > TIA, > Richard A. DeVenezia > > ______________________________________________ > R-help@r-project.org 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org 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.