Dear John and Brian, My point about colour-blindness was partly tongue-in-cheek, but I think that it's a bad choice to have the second and third colours in the default palette as red and green.
Regards, John > -----Original Message----- > From: John Maindonald [mailto:john.maindon...@anu.edu.au] > Sent: February-19-09 2:54 AM > To: Prof Brian Ripley > Cc: John Fox; r-devel@r-project.org; 'Martin Maechler' > Subject: Re: [Rd] plot.lm: "Cook's distance" label can overplot point labels > > Actually, the contours and the smooth are currently printed with > col=2. This prints satisfactorily in grayscale. Colours ("orange" > and "darkred" as well as col=2) are also used in termplot. > > Does the stricture against "colour" extend to grayscale? Does it > apply to lines as well as text? > > 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 19/02/2009, at 5:58 PM, Prof Brian Ripley wrote: > > > On Wed, 18 Feb 2009, John Fox wrote: > > > >> 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). > > > > Or using a black-and-white device. We have not hitherto assumed a > > colour device in 'stats' graphics, and given how often they are > > printed I don't think we want to start. > > > > As so often, it seems that what looks good is in the eye of the > > beholder. If the two of you can agree on something that you both > > see is a definite improvement, please provide a patch and examples > > to try to persuade everyone else. (As a Wishlist item on R-bugs, so > > it gets recorded.) > > > >> > >> 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. > > > > > > -- > > Brian D. Ripley, rip...@stats.ox.ac.uk > > Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ > > University of Oxford, Tel: +44 1865 272861 (self) > > 1 South Parks Road, +44 1865 272866 (PA) > > Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
