Sorry, legend= was omitted: plot(1:10) legend("topleft", legend = This ~ study ~ italic(n) == 3293)
On 3/18/07, Chabot Denis <[EMAIL PROTECTED]> wrote: > Thank you Marc, Jim and Gabor, > > I like the solution with "expression", nice and simple. Gabor, your > solution did not work, probably just a matter of putting the text > inside an expression? > > However it would be nice if the help system pointed to it. A search > on "italics" brought me nothing, one on "italic" gave me 4 hits, none > useful. And reading the help on plotmath, I found no mention of italic > (). Where can we suggest additions to the help system? > > I must plead guilty to have forgotten a RSiteSearch before posting. I > just did and I think I might have figured out something out there. > But your answers were nice and to the point! > > Cheers, > > Denis > Le 07-03-17 à 23:30, Marc Schwartz a écrit : > > > On Sat, 2007-03-17 at 21:56 -0500, Marc Schwartz wrote: > >> On Sat, 2007-03-17 at 22:01 -0400, Chabot Denis wrote: > >>> Hi, > >>> > >>> As part of the legend to a plot, I need to have the "n" in italics > >>> because it is a requirement of the journal I aim to publish in: > >>> "This study, n = 3293" > >>> > >>> Presently I have: > >>> legend(20, 105, "This study, n = 3293", pch=1, col=rgb(0,0,0,0.5), > >>> pt.cex=0.3, cex=0.8, bty="n") > >>> > >>> I suppose I could leave a blank in place of the "n", then issue a > >>> text call where I'd use font=3 for a single letter, "n". But it will > >>> be tricky to find the exact location to use. > >>> > >>> Is there a way to switch to font=3 just for one letter within a > >>> string? > >>> > >>> Thanks in advance, > >>> > >>> Denis Chabot > >> > >> Denis, > >> > >> Try something like this: > >> > >> plot(20, 100) > >> > >> leg <- legend(20, 105, "This study, = 3293", pch = 1, > >> col=rgb(0,0,0,0.5), pt.cex = 0.3, cex = 0.8, > >> bty = "n") > >> > >> text(leg$text$x + strwidth("This study, ", cex = 0.8), > >> leg$text$y, "n", font = 3, cex = 0.8, adj = c(0, 0.5)) > >> > >> > >> Note that legend returns a list structure, which contains the x and y > >> coordinates of the start of the text strings that are plotted. So > >> I get > >> that information for your line of text. > >> > >> Next, I use strwidth() to calculate, in user coordinates, the > >> length of > >> the characters preceding the 'n', including spaces. We add that > >> distance to the x coordinate returned in the legend call. > >> > >> I also use the 'adj' argument in the text() call, so that it is in > >> synch > >> with the same parameters in legend() for alignment with the other > >> letters. > >> > >> See ?strwidth for more information. > >> > >> You may have to tweak the horizontal spacing of the 'n' a bit, > >> depending > >> upon the rest of your graph. > > > > Denis, > > > > I thought of another approach, using plotmath. > > > > First, create a text expression, specifying that the 'n' should be > > italicized. Then use that expression in the legend() call. > > > > txt <- expression(paste("This study, ", italic(n), " = 3293")) > > > > plot(20, 100) > > > > legend(20, 105, txt, pch = 1, col=rgb(0,0,0,0.5), > > pt.cex = 0.3, cex = 0.8, bty = "n") > > > > > > That's easier that the first solution. See ?plotmath > > > > HTH, > > > > Marc Schwartz > > > > > > ______________________________________________ R-help@stat.math.ethz.ch 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.