Deepayan, Paul: Thanks very much for the very useful leads. I just spent some time this afternoon implementing your suggestions and my early test results are very encouraging.
Paul, I understand the potential device re-sizing issue with the convert family of functions in grid, and will be in touch in case it becomes problematic for my applications. I very much look forward to your upcoming "R Graphics" book and wish you the best in completing it. Best Regards, Bill > -----Original Message----- > From: Paul Murrell [mailto:[EMAIL PROTECTED] > Sent: Thursday, June 02, 2005 4:57 PM > To: Pikounis, Bill [CNTUS] > Cc: Deepayan Sarkar; [email protected] > Subject: Re: [R] panel.axis() & grid/lattice settings > > > Hi > > > Deepayan Sarkar wrote: > > On Wednesday 01 June 2005 05:43, Pikounis, Bill [CNTUS] wrote: > > > >>Hello, > >>I wish to customize the tick marks and labels of axes in > panels produced by > >>high-level lattice functions, namely xyplot. I know I can > use the scales > >>argument to specify values for rot, cex, etc. in the top-level call. > >> > >>However, I am interested in determining values for cex and > rot based on the > >>current panel / viewport and device. More specifically, I > would like to > >>make adjustments when tick labels overlap on the x-axis, > such as labels of > >>a factor. If I use base graphics, par("cin") or par("cxy") > or strwidth(), > >>etc. can be used to develop an algorithm to adjust cex or/and rot if > >>needed. > >> > >>I am trying to determine the parameters/settings in grid > analogous to > >>par("cin"), etc. mentioned above, knowing that par() has no > effect in > >>lattice / grid. I have dug around the sources for grid and > lattice but > >>cannot seem to come up with such parameters -- most notably > something like > >>strwidth(). I see that panel.axis() has a check.overlap argument for > >>labels, but I could not trace down the actual code to see > how that works. > >>What have I overlooked, or where should I be looking? > > > > > > Paul may be able to give a more insightful answer, but grid > allows a string to > > determine it's width in terms of itself, e.g.: > > > > unit(1, "strwidth", data = "foo") > > > Or just stringWidth("foo") (and of course stringHeight("foo")). > > > > If you want to convert that into, say, inches, you could use > > > > > >>convertX(unit(1, "strwidth", data = "foo"), "inches", TRUE) > > > > [1] 0.2344092 > > > > I think this would depend on the gpars() in effect, in > particular fontsize. > > > Yep. There's also grobWidth(textGrob("foo")), which gives > you not just > the size of a string, but the size of a text graphical object. The > difference is that a text graphical object can include > information about > where it will be drawn, in what font, and so on. For example, > grobWidth(textGrob("foo", gp=gpar(fontfamily="mono", cex=2))) is very > different from stringWidth("foo"). If you want to determine > the size > of some text that you want to draw as part of the panel axis AND you > want it to look like the text that lattice would have drawn, then > something like this might give you what you want: > > grobWidth(textGrob("your label", > gp=do.call("gpar", > trellis.par.get("axis.text")))) > > It is also important that you do these calculations within a panel > function so that they get evaluated within the appropriate context > (i.e., higher-level lattice graphical parameter settings have been > enforced). The result of the above call to grobWidth() could be very > different if evaluated in some other context. > > Finally, if you use convertX() (or any of its ilk), be aware that > changes in the device size (e.g., resize a window) could make the > calculations invalid. Maybe we could follow this up on the r-devel > mailing list if you think this will be an issue. > > Paul > > > >>Indirectly related, setting outside=TRUE in a panel.axis() > call does not > >>produce visible labels, perhaps due to "issues of clipping" > as mentioned in > >>its help page. How might one disable clipping for the > current panel / > >>viewport? > > > > > > At the grid level, there's a 'clip' argument to > 'viewport()'. In lattice, > > these are chosen from > > > > > >>str(trellis.par.get("clip")) > > > > List of 2 > > $ panel: chr "on" > > $ strip: chr "on" > > > > (In case you are using 'trellis.focus', that can set clipping off.) > > > > Deepayan > > > > ______________________________________________ > > [email protected] mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > > -- > 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/ > > [[alternative HTML version deleted]] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
