Maybe this is helpful. Install ggplot2.
#Create a small example x <- seq(1:20) y <- (2*x) + rnorm(length(x),0,1) id <- rep(1:5,each=4) dat <- data.frame(x,y,id) library(ggplot2) p <- ggplot(dat,aes(x=x,y=y,colour=factor(id))) p <- p + geom_point() p If this is not the correct structure, maybe including an example will help. For example, you can output your data or a subset with dput. dput(dat) structure(list(x = 1:20, y = c(3.52519254181276, 5.24044281644567, 7.47776852203483, 7.4451075539517, 9.85463703204831, 12.533885478775, 14.2364347537978, 15.6031588004515, 17.2400819084948, 20.2053499115504, 21.4994848677570, 23.6354345765166, 24.5523452698087, 27.3185637999515, 28.5812163905758, 32.6805764070542, 37.0894956595204, 35.0009332656281, 39.6077996102053, 41.0996392969496), id = c(1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 5L, 5L, 5L, 5L)), .Names = c("x", "y", "id"), row.names = c(NA, -20L), class = "data.frame") Best, Juliet On Wed, Aug 5, 2009 at 7:00 PM, per freem<perfr...@gmail.com> wrote: > hi all, > > suppose I have a file with several columns, and I want to plot all points > that meet a certain condition (i.e. all points in columns A and B that have > a value greater than such and such in column C of the data) in a new but > random color. That is, I want all these points to be colored differently > but I dont care what color. The only concern is that the points will be > colored as differently from each other as possible. > > The specific example I have is a file with three columns, X, Y and ID. I > want to plot all rows from X, Y (i.e. all points) that have the same value > (say 1) in their ID column as one color, all points from X, Y that have the > same ID column value (say 2) as a different color, etc. I dont know ahead > of time how many values the ID column will have so I can't write a separate > plot statement for each of these sets of X, Y rows that have the same ID > value. > > Is there a way to express this in R? > > thank you. > Is there a way to do this? > > [[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. > ______________________________________________ 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.