abline(0,1) is somewhere in the upper-left corner which you are unable to see. At least the first distribution seems to have a larger mean than the second one (i.e. they are not the same distribution).
Regards, Yihui -- Yihui Xie <xieyi...@gmail.com> Phone: 515-294-6609 Web: http://yihui.name Department of Statistics, Iowa State University 3211 Snedecor Hall, Ames, IA On Mon, Nov 2, 2009 at 10:33 AM, carol white <wht_...@yahoo.com> wrote: > if I have the two following matrices, abline(0,1) doesn't go through. QQplot > is attached. > > [,1] [,2] [,3] [,4] [,5] > 2.149644 1.992864 3.346375 2.793511 3.428230 > 1.100762 2.152981 2.735401 2.175185 3.323058 > 1.212406 2.131813 2.672598 2.389996 3.242490 > 1.183770 1.908633 2.661237 2.590545 2.906059 > 1.665190 1.778923 2.636062 2.475619 4.013407 > > > 0.601 0.083 0.520 0.920 -0.007 > -0.778 0.427 -0.605 -0.066 -0.283 > -0.599 0.348 -0.693 0.284 -0.436 > -0.519 0.081 -0.590 0.678 -1.095 > 0.009 -0.253 -0.940 0.526 1.623 > > > --- On Mon, 11/2/09, David Winsemius <dwinsem...@comcast.net> wrote: > >> From: David Winsemius <dwinsem...@comcast.net> >> Subject: Re: [R] qqplot >> To: "carol white" <wht_...@yahoo.com> >> Cc: r-h...@stat.math.ethz.ch >> Date: Monday, November 2, 2009, 8:17 AM >> >> On Nov 2, 2009, at 10:40 AM, carol white wrote: >> >> > Hi, >> > We could use qqplot to see how two distributions are >> different from each other. To show better how they are >> different (departs from the straight line), how is it >> possible to plot the straight line that goes through them? I >> am looking for some thing like qqline for qqnorm. I thought >> of abline but how to determine the slope and intercept? >> >> I always assumed that the intercept was zero and the slope >> = unity. >> >> y <- rt(200, df = 5) >> qqnorm(y); qqline(y, col = 2) >> qqplot(y, rt(300, df = 5)) >> abline(0, 1, col="red") >> >> I am open to education if that assumption is too >> simplistic, but you have not offered anything in the way of >> a counter-example. >> >> > >> == >> >> David Winsemius, MD >> Heritage Laboratories >> West Hartford, CT >> >> > > > > ______________________________________________ > 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.
