Hello and thank you for this first response I'll rephrase what I mean by "more general": in a case where I have only 2 levels in groups, but in which I have more than 2 levels for variable s, and in a case where the second bar is not necessarily higher than the first. Thanks in advance. Best regards,
David Gouache Arvalis - Institut du Végétal -----Message d'origine----- De : Deepayan Sarkar [mailto:[EMAIL PROTECTED] Envoyé : vendredi 27 avril 2007 19:52 À : GOUACHE David Cc : r-help@stat.math.ethz.ch Objet : Re: [R] add arrows to barchart with groups On 4/27/07, GOUACHE David <[EMAIL PROTECTED]> wrote: > Hello Rhelpers, > > I am trying to represent the following data (hereafter named donnees) in a > barchart with a grouping variable : > > > site traitement date s res > 1 NT 17/10/2005 normal 76.2 > 1 T 17/10/2005 normal 103.2 > 1 NT 23/11/2005 tardif 81.6 > 1 T 23/11/2005 tardif 98 > 2 NT 15/10/2005 normal 72.71 > 2 T 15/10/2005 normal 94.47 > 2 NT 15/11/2005 tardif 79.65 > 2 T 15/11/2005 tardif 94.7 > > barchart(res~s|site,groups=traitement,data=donnees) > > What I'd like to do is for each site represent with an arrow the difference > in value of variable res between normal and tardif values of variable s. > I've found one way of doing it: > > > trellis.focus("panel",1,1) > xx<-trellis.panelArgs()$x > yy<-trellis.panelArgs()$y > panel.arrows(as.numeric(xx)[c(1,3)]-0.1,yy[c(1,3)],as.numeric(xx)[c(1,3)]-0.1,yy[c(2,4)],lwd=2,code=3) > panel.text(as.numeric(xx)[c(1,3)]-0.35,c(87,87),paste(yy[c(2,4)]-yy[c(1,3)],"\nq/ha"),font=2) > trellis.focus("panel",2,1) > xx<-trellis.panelArgs()$x > yy<-trellis.panelArgs()$y > panel.arrows(as.numeric(xx)[c(1,3)]-0.1,yy[c(1,3)],as.numeric(xx)[c(1,3)]-0.1,yy[c(2,4)],lwd=2,code=3) > panel.text(as.numeric(xx)[c(1,3)]-0.35,c(87,87),paste(yy[c(2,4)]-yy[c(1,3)],"\nq/ha"),font=2) > trellis.unfocus() > > But I would prefer doing this within a custom panel function so I can apply > it more generally, and I haven't been able to figure out how... > Could anyone give me a hand? The obvious analog (just copy/pasting your code) is: my.panel <- function(x, y, ...) { panel.barchart(x, y, ...) xx <- x yy <- y panel.arrows(as.numeric(xx)[c(1,3)]-0.1, yy[c(1,3)], as.numeric(xx)[c(1,3)]-0.1, yy[c(2,4)], lwd = 2, code = 3) panel.text(as.numeric(xx)[c(1,3)] - 0.35, c(87,87), paste(yy[c(2,4)] - yy[c(1,3)], "\nq/ha"), font=2) } and this seems to work: barchart(res~s|site,groups=traitement,data=donnees, panel = my.panel) barchart(res~s|site,groups=traitement,data=donnees, panel = my.panel, origin = 0) I'm not sure what else you are looking for and what you mean by "more general". For example, it's not clear what you want to happen If you have more than 2 levels in 'groups', or if the second bar is not always higher than the first. -Deepayan ______________________________________________ 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.
