Did you read the help page for qqnorm? The return value has the x and y coordinates used, you can just do something like:
> tmp <- qqnorm( resid(test.lm) ) > identify(tmp, , names(resid(test.lm)) ) Or the plot.lm function has an argument id.n that automatically labels the n most extreme values: > plot( test.lm, 2, id.n=10 ) Those both worked in my tests, if they are not working for you then send a reproducible example (include data, see ?dput) and maybe we can help further. -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of casperyc > Sent: Thursday, November 18, 2010 11:50 AM > To: r-help@r-project.org > Subject: Re: [R] how exactly does 'identify' work? > > > Hi, > > I think the problem is > > 1 - when a linear model is fitted, ploting the qqnorm( test.lm$ res ) > we dont 'know' what values are actually being used on the y-axis; and > how do we refer to the ‘Index’ on the x-axis?? > therefore, i dont know how to refer to the x and y coordinates in > the > identify function > > 2 - i have tried using the stdres function in the MASS library, to > extract > the standardised > residuals and plot them manully, ( using the plot ) function. > this way, the problem is we have to SORT the residuals first in > increasing order to reproduce the same qqnorm plot, in that case, > 'identify' > function works, however, that CHANGES the order, i.e. it wont return > the > original A:Z ( row.names ) label. > -- > View this message in context: http://r.789695.n4.nabble.com/how- > exactly-does-identify-work-tp3045953p3049357.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.
