Melissa, par(new=T) works as many times as you use it. You don't provide data, but (assuming it is not NULL) more likely your n=500 qqplot was just obscuring the points of the n=50 plot.
Reverse the order (i.e. qqplot 500 first, 50, 5 last) and see if all three are there (as there are more 500 you should still see green on the extremes). Second, you say you want "lines" but used pch=20. replace with type='l' to get lines (may also help with your main problem). If you want to stick with points and your device supports it, you can consider semi-transparent colors. Cheers On Thu, Feb 9, 2012 at 9:00 PM, Melrose2012 <melissa.patric...@stonybrook.edu> wrote: > Hi Everyone, > > I want to make 3 lines on the same graph (not as subplots, all in the same > window, one on top of each other) and I want them to be quantile-quantile > plots (qqplot). Essentially, I am looking for the equivalent of Matlab's > "hold on" command to use with qqplot. I know I can use 'points' or 'lines', > but these do not give me a qqplot (only appear to work as scatter plots). I > found the syntax 'par(new=TRUE)' but that only seems to work for two lines, > not for three. > > My script currently looks like: > > qqplot(nq.n5,tq.n5,col="red",xlab="Normal Distribution Quantiles",ylab="t > Distribution Quantiles",main="Quantile-Quantile Plot of Normal vs > t-Distribution for Various Sample Sizes",pch=20) > par(new=TRUE) > qqplot(nq.n50,tq.n50,col="blue",xlab="",ylab="",pch=20). > par(new=TRUE) > qqplot(nq.n500,tq.n500,col="green",xlab="",ylab="",pch=20) > legend("topleft",c("n=5","n=50","n=500"),fill=c("red","blue","green")) > > I realize that this only plots the first and the third qqplot because by > doing par(new=TRUE) again, it gets rid of the middle one. I don't know how > to get around this and get all 3 lines on the same plot. > > Can anyone please help me with this syntax? > > Thank you very much for your time and advice! > > Cheers, > Melissa > > -- > View this message in context: > http://r.789695.n4.nabble.com/making-multiple-lines-using-qqplot-tp4375273p4375273.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.