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.