PGFPlotsX: annotate outside plot area

[Tamas_Papp]

using PGFPlotsX
@pgf Axis({ xmin = 0, xmax = 1, ymin = 0, ymax = 1, clip = false},
          Plot({ only_marks }, Table(rand(5), rand(5))),
          raw"\node[label={inside},circle,fill,inner sep=2pt,red] at (axis cs:0.5,0.5) {};",
          raw"\node[label={outside},circle,fill,inner sep=2pt,red] at (axis cs:0,0.5) {};")