I suppose to be more clear, what I mean is that I was hoping to find upper/lower bounding parameter/rule, similar to "rule = 1" in the approxfun command (which returns NA for any specified x-value outside the defined domain). Actually, that's exactly what I would like: a stepfun function that has a bounded domain.
And reading the phrase, "range of 'x' values to use" indicated just this. I'm now aware that it gets forwarded on to the plot command, but that doesn't solve the problem of the points being chosen for the lines in the plot extending beyond the desired range. Instead I'm now simply working with approxfun, but this is something of a compromise as now plotting involves a series of extra commands to draw the step function (in particular I was drawing the function with 'verticals = FALSE' so now I've written a separate function to draw the approxfun within the bounds of the function using a series of line segments... although this is something of a pain in the arse). Alternatively I can stick with the stepfun and either hack up the display (i.e. play with the axes and margins), or hack up the stepfun itself (add two more plateaus, one on each side of my "domain", with values that are beyond the range that I ever intend on displaying in the figure). All of these possibilities aren't exactly elegant, however. On Dec 31, 11:35 am, "Stavros Macrakis" <macra...@alum.mit.edu> wrote: > > On Tue, 30 Dec 2008, m.u.r. wrote: > >> according to the documentation, the xlim parameter should bound the > >> range of the function being plotted, and is returned as the extreme > > On Wed, Dec 31, 2008 at 4:18 AM, Prof Brian Ripley > <rip...@stats.ox.ac.uk> replied: > > > Wheere does it say that? > > True, it doesn't say that. As you say, ?plot.stepfun says > > > xlim,ylim: numeric(2) each; range of 'x' or 'y' values to use.... > > and ?plot.window says > > xlim, ylim: numeric vectors of length 2, giving the x and y > coordinates [sic] ranges. > > ...both of which are rather vague, not saying what the *effect* of > these "ranges" is. Perhaps a more precise description would be: > > xlim, ylim: each is numeric(2) and defines the range of the x and > y scales. cf. xaxs; xpd. > > More experienced users can perhaps come up with better language. > > -s > > ______________________________________________ > r-h...@r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guidehttp://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.
