Dear John, > -----Original Message----- > From: John Maindonald [mailto:john.maindon...@anu.edu.au] > Sent: February-18-09 4:57 PM > To: John Fox > Cc: 'Martin Maechler'; r-devel@r-project.org > Subject: Re: [Rd] plot.lm: "Cook's distance" label can overplot point labels > > Dear John - > The title above the graph is also redundant for the first of the > plots; do we want to be totally consistent? I am not sure.
Why not? "A foolish consistency is the hobgoblin of little minds," but maybe this isn't a foolish consistency. > > It occurs to me that the text "Cook's distance", as well as the > contours, might be in red. That would provide a nice visual cue (for those who aren't colour blind). Best, John > Regards > John. > > John Maindonald email: john.maindon...@anu.edu.au > phone : +61 2 (6125)3473 fax : +61 2(6125)5549 > Centre for Mathematics & Its Applications, Room 1194, > John Dedman Mathematical Sciences Building (Building 27) > Australian National University, Canberra ACT 0200. > > > On 18/02/2009, at 12:27 PM, John Fox wrote: > > > Dear John, > > > > It occurs to me that the title above the graph, "Residuals vs. > > Leverage," is > > entirely redundant since the x-axis is labelled "Leverage" and the y- > > axis > > "Studentized residuals." Why not use the title above the graph for > > "Cook's > > distance countours"? > > > > Regards, > > John > > > >> -----Original Message----- > >> From: r-devel-boun...@r-project.org [mailto:r-devel-boun...@r-project.org > >> ] > > On > >> Behalf Of John Maindonald > >> Sent: February-17-09 5:54 PM > >> To: r-devel@r-project.org > >> Cc: Martin Maechler > >> Subject: [Rd] plot.lm: "Cook's distance" label can overplot point > >> labels > >> > >> The following code demonstrates an annoyance with plot.lm(): > >> > >> library(DAAGxtras) > >> x11(width=3.75, height=4) > >> nihills.lm <- lm(log(time) ~ log(dist) + log(climb), data = nihills) > >> plot(nihills.lm, which=5) > >> > >> OR try the following > >> xy <- data.frame(x=c(3,1:5), y=c(-2, 1:5)) > >> plot(lm(y ~ x, data=xy), which=5) > >> > >> The "Cook's distance" text overplots the label for the point with the > >> smallest residual. This is an issue when the size of the plot is > >> much > >> less than the default, and the pointsize is not reduced > >> proportionately. > >> > >> > >> I suggest the following: > >> xx <- hii > >> xx[xx >= 1] <- NA > >> ## Insert new code > >> fracht <- (1.25*par()$cin[2])/par()$pin[2] > >> ylim[1] <- ylim[1] - diff(ylim)*max(0, fracht-0.04) > >> ## End insert new code > >> plot(xx, rsp, xlim = c(0, max(xx, na.rm = TRUE)), > >> ylim = ylim, main = main, xlab = "Leverage", > >> ylab = ylab5, type = "n", ...) > >> > >> Then, about 15 lines further down, replace > >> legend("bottomleft", legend = "Cook's distance", > >> lty = 2, col = 2, bty = "n") > >> > >> by > >> legend("bottomleft", legend = "Cook's distance", > >> lty = 2, col = 2, bty = "n", y.intersp=0.5) > >> > >> If this second change is not made, then one wants fracht <- > >> (1.5*par() > >> $cin[2])/par()$pin[2] > >> I prefer the "Cook's distance" text to be a bit closer to the x-axis, > >> as it separates it more clearly from any point labels. > >> > >> John Maindonald email: john.maindon...@anu.edu.au > >> phone : +61 2 (6125)3473 fax : +61 2(6125)5549 > >> Centre for Mathematics & Its Applications, Room 1194, > >> John Dedman Mathematical Sciences Building (Building 27) > >> Australian National University, Canberra ACT 0200. > >> > >> ______________________________________________ > >> R-devel@r-project.org mailing list > >> https://stat.ethz.ch/mailman/listinfo/r-devel > > > > ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel