[R] Grouping stripchart markers

Dimitris Rizopoulos d.rizopoulos at erasmusmc.nl
Sun Feb 15 08:52:59 CET 2009

well, for a simple stripchart (i.e., default method) you can use 
something like the following:

x <- rnorm(9)
cl <- c(1,1,1,2,2,2,3,3,3)

plot(range(x), c(0, 1), type = "n", yaxt = "n", ann = FALSE)
points(x, rep(0.5, length(x)), pch = cl)

I hope it helps.


Sam Player wrote:
> If I have a dataset grouped into 3 classes, how can I construct a 
> stripchart where the markers are different for each class, e.g. a cross 
> for 1, square for 2 and circle for 3. In the example below I try to 
> define the marker type by the class but this only changes all the 
> markers from the default squares into circles. I am assuming I need to 
> set pch as an argument in par but am unsure how to proceed.
> data <- rnorm(9)
> class <- c(1,1,1,2,2,2,3,3,3)
> x <- data.frame(data,class)
> stripchart(x[,1], pch=x[,2])
> Thanks,
> Sam.
> ______________________________________________
> R-help at 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.

Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014

More information about the R-help mailing list