On 2/4/2006 3:50 PM, ivo welch wrote: > [resent, plus small addition; I do not understand why gmail sent a > weird charset.] > > Dear R wizards: > > I would love to write a general function that matches the slope of a plotted > line in an xy-plot at a particular x,y location. something like > > x<- (1:10)^2; y<- 40:50; > plot( x,y, type="l", xlim=c(0,90) ) > srt.at5 = text.at.current.plot.with.slope( x, y, 5); > text( x[5],y[5], pos=3, srt=srt.at.5); > > to do this, I first need to compute the function slope around x[5], which is > an easy task. alas, the harder task is that I need to scale this by the > plot aspect ratio and the axes. How can a function read this from the > current plot?
I haven't done this, but you can presumably work it out from the conversions implied by the "fig", "fin", "plt", and/or "usr" values. > > (Has someone written such a function, perhaps more embellished, to save me > the debugging effort?) > > Or, is there an alternative to srt, which slopes the text relative to the > existing scale? > > *** come to think of it, what I would really like is the ability of > text to 'snake' itself along the line itself. I doubt that this is > easily possible, but I just wanted to ask. Using strsplit and strwidth you should be able to do it, but it will probably look quite ugly. Duncan Murdoch ______________________________________________ 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