Hi Matthias, please see below for some code example.
Matthias von Rad wrote: > Hi, > I am doing lots of scatterplots for my dissertation and to make the > comparable, I would like to have equal x- amd - y axis. Can I specify > their scale? > Another question adresses overlay scatterplots. Having prae and post > measures for each case, is it possible to have them in one graph with > symbols or colors for prae and post. ### first we create some hypothetical data pre.x <- runif(n=100, min=0, max=10) pre.y <- 1.5+2*pre.x+rnorm(n=length(pre.x), mean=pre.x, sd=1) post.x <- runif(n=100, min=0, max=10) post.y <- 20-3*post.x+rnorm(n=length(post.x), mean=post.x, sd=1) ## let's construct a plot from scratch, using type="n" to have an ## empty plotting area plot(x=1,y=1, type="n", xlim=c(0,10), ylim=c(0,20), axes=FALSE, xlab="My X-Labels", ylab="My Y-Labels") axis(side=1, at=seq(from=0, to=10, by=2.5)) axis(side=2, at=seq(from=0, to=20, by=5)) points(x=pre.x, y=pre.y, col="green", pch=19) points(x=post.x, y=post.y, col="red", pch=19) ### and this makes it easy to find out which 'pch'-number plots which ### symbol: plot(x=0:25, y=0:25, pch=0:25) I hope this helps. Best, Roland ______________________________________________ R-help@stat.math.ethz.ch 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.