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? (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? help appreciated. sincerely, /ivo welch [[alternative HTML version deleted]]