Sun, here are some options. You can use points() to add new points to a plot, or you can use par(new=T) to plot a new graph in a previously- used device. So, in code the two options would look like:
plot(x1, y1, pch=1) points(x2, y2, pch=2) (this preserves the original axes) or plot(x1, y1, pch=1) par(new=T) plot(x2, y2, pch=2) for which the new plot will have new axes etc., so if you want to perserve the axis characteristics then you need to do so seperately. I did not include details about subsetting. I hope that this helps. Andrew On Sun, Sep 19, 2004 at 05:02:21PM -0500, Sun wrote: > Hello, Rusers: > > I have a question to ask for your help. The data has three columns: a, b and > c. > > We need to draw an overlaid plot of curves of "a" versus "b" for different > c. That is, draw many curves in one plot and each curve uses a different > symbol. > > Does R have such functions? I have searched for a while. But seems not. I am > new to R. Your help is highly appreciated. > > Many thanks. Looking forward to your response, > > Sun > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html -- Andrew Robinson Ph: 208 885 7115 Department of Forest Resources Fa: 208 885 6226 University of Idaho E : [EMAIL PROTECTED] PO Box 441133 W : http://www.uidaho.edu/~andrewr Moscow ID 83843 Or: http://www.biometrics.uidaho.edu No statement above necessarily represents my employer's opinion. ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html