Say I want to display a web data stream in real time in a plot in R. Is there a way, to just draw and undraw the most recent text box or segment over the existing plot, rather than drawing the entire ...

I have a fiddley little problem! I am trying to get a superscript (i.e. the -1 in "Mg:Ca(µmol mol-1)" into a text grob but can't find the correct annotation of the script: Axis labels yle...