I think I may understand what you want. I 'd say the first thing to do is to combine the 3 matrices into a single data frame with a column for the values of A, B C
Here is a mock-up with something like what I mean. I just used two columns of data for the mock-up. Then, you can reshape the data using melt() from the reshape2 package and then graph the data using ggplot from the ggplot2 package. Is this something like what you want? ============================================================= library(ggplot2) library(reshape2) A <- data.frame( m = (rep("A", 10)) , b=rnorm(10), c = rnorm(10)) B <- data.frame( m = (rep("B", 10)) , b=rnorm(10), c = rnorm(10)) C <- data.frame( m = (rep("C", 10)) , b=rnorm(10), c = rnorm(10)) mydata <- rbind( A, B, C ) names(mydata) <- c( "group", "k1", "k2" ) mdata <- melt(mydata) p <- ggplot( mdata , aes(variable, value , colour = variable )) + geom_boxplot() + facet_grid( group ~ .) p ============================================================== John Kane Kingston ON Canada > -----Original Message----- > From: hannah....@gmail.com > Sent: Thu, 28 Jun 2012 16:29:54 -0400 > To: r-help@r-project.org > Subject: [R] Help > > Dear all, > I need some help on plotting multiple boxplots on one figure. > I have three matrix A, B and C. Each of them is a 1000 by 10 matrix. > The 10 columns of all three matrix correspond to the > 10 values of the same parameter, say k=1, ..., 10. > I want to make a plot where x axis represents different values of k. > For each k value, I want to plot three boxplots, one on top of another. > For example, for k=1, I want to draw three boxplot based on the first > column of A, B and C respectively. Similarly, I do the same for the rest > of > k values. > Can some one give me some hint on this? > Thank you so much. > Hannah > > [[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. ____________________________________________________________ FREE ONLINE PHOTOSHARING - Share your photos online with your friends and family! Visit http://www.inbox.com/photosharing to find out more! ______________________________________________ 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.