>>>>> "MM" == Martin Maechler <[EMAIL PROTECTED]> >>>>> on Tue, 26 Apr 2005 12:13:38 +0200 writes:
>>>>> "JMd" == John Maindonald <[EMAIL PROTECTED]> >>>>> on Tue, 26 Apr 2005 15:44:26 +1000 writes: JMd> The web page http://wwwmaths.anu.edu.au/~johnm/r/plot-lm/ JMd> now includes files: JMd> plot.lm.RData: Image for file for plot6.lm, a version of plot.lm in JMd> which JMd> David Firth's Cook's distance vs leverage/(1-leverage) plot is plot 6. JMd> The tick labels are in units of leverage, and the contour labels are JMd> in units of absolute values of the standardized residual. JMd> plot6.lm.Rd file: A matching help file JMd> Comments will be welcome. MM> Thank you John! MM> The *.Rd has the new references and a new example but MM> is not quite complete: the \usage{} has only 4 captions, MM> \arguments{ .. \item{which} ..} only mentions '1:5' --- but MM> never mind. MM> One of the new examples is MM> ## Replace Cook's distance plot by Residual-Leverage plot MM> plot(lm.SR, which=c(1:3, 5)) MM> and -- conceptually I'd really like to change the default from MM> 'which = 1:4' to the above MM> 'which=c(1:3, 5))' MM> This would be non-compatible though for all those that have MM> always used the current default 1:4. MM> OTOH, "MASS" or Peter Dalgaard's book don't mention plot(<lm fit> ) MM> or at least don't show it's result. MM> What do others think? MM> How problematic would a change be in the default plots that MM> plot.lm() produces? JMd> Another issue, discussed recently on r-help, is that when the model JMd> formula is long, the default sub.caption=deparse(x$call) is broken JMd> into multiple text elements and overwrites. MM> good point! JMd> The only clean and simple way that I can see to handle JMd> is to set a default that tests whether the formula is JMd> broken into multiple text elements, and if it is then JMd> omit it. Users can then use their own imaginative JMd> skills, and such suggestions as have been made on JMd> r-help, to construct whatever form of labeling best JMd> suits their case, their imaginative skills and their JMd> coding skills. MM> Hmm, yes, but I think we (R programmers) could try a bit harder MM> to provide a reasonable default, e.g., something along MM> cap <- deparse(x$call, width.cutoff = 500)[1] MM> if((nc <- nchar(cap)) > 53) MM> cap <- paste(substr(cap, 1, 50), "....", substr(cap, nc-2, nc)) MM> {untested; some of the details will differ; MM> and the '53', '50' could depend on par("..") measures} In the mean time, I came to quite a nice way of doing this: if(is.null(sub.caption)) { ## construct a default: cal <- x$call if (!is.na(m.f <- match("formula", names(cal)))) { cal <- cal[c(1, m.f)] names(cal)[2] <- "" # drop " formula = " } cc <- deparse(cal, 80) nc <- nchar(cc[1]) abbr <- length(cc) > 1 || nc > 75 sub.caption <- if(abbr) paste(substr(cc[1], 1, min(75,nc)), "...") else cc[1] } I'm about to commit the current proposal(s) to R-devel, **INCLUDING** changing the default from 'which = 1:4' to 'which = c(1:3,5) and ellicit feedback starting from there. One thing I think I would like is to use color for the Cook's contours in the new 4th plot. Martin <.............. lots deleted ..........> ______________________________________________ R-devel@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-devel