Hi
Duncan Murdoch wrote: > I've moved this from r-help to r-devel. > > On 3/23/2006 8:17 PM, Paul Murrell wrote: > >>> >>> Paul, >>> If I read your comments correctly, the problem with manipulating the >>> graph history is with saved histories across sessions/versions. Is >>> there any reason not to manipulate it *within* a session? I never >>> save plots for re-use in R. Re-running code is usually best for me. >>> But I would find it handy to fiddle with the display list in a >>> session. >> >> >> >> That is *one* problem with the display list. Messing directly with >> the display list *within a session* is *less* dangerous, but R's >> behaviour if you do that is "undefined". >> >> The display list is technically an internal structure for R's internal >> use. We can't stop you playing with it, but I do not encourage it and >> it is not officially supported. >> >> There are a number of simple things that you could do to the display >> list that should work, but providing proper support for general >> manipulations of the display list would require a significant amount >> of (re)design of the R graphics code. >> >> Paul >> >> p.s. These comments apply to the display list in R's "graphics >> engine". The 'grid' package also maintains a display list, and that >> has been designed to support more general manipulations. > > > Are we talking about the same thing? I think Peter is only thinking of > manipulating the .SavedPlots variable, which is a Windows-only object > holding plot history. I imagine the entries in .SavedPlots[[5]] are the > things that you are worried about, and I agree people shouldn't play > with those, they should be using grid instead with its documented > interface. Sorry, I came into the discussion a bit late, so there's a good chance I have misunderstood. Within a session, manipulation of .SavedPlots (via the appropriate interface) seems reasonable (i.e., manipulations involving an entire "page" of output as the basic unit). Warnings about use *between* sessions still apply though. Paul > If we do warn people off manipulating .SavedPlots, then I think it > should be a higher priority to implement some manipulations ourselves, > e.g. "[<-.SavedPlots", to allow entries to be moved around or deleted in > the list. > > Duncan -- Dr Paul Murrell Department of Statistics The University of Auckland Private Bag 92019 Auckland New Zealand 64 9 3737599 x85392 [EMAIL PROTECTED] http://www.stat.auckland.ac.nz/~paul/ ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
