PGFplots in LyX

[Wolfgang Engelmann]

I tried to use PGFplots in LyX. It is difficult for me, but after some 
time I managed to get one figure drawn.
However, I do not know how to plot this figure in the way floating 
objects are used so that I can cross reference to it and LyX takes care 
of where this figure will be placed.
I did not find a cue in Ian's hint

http://chelseas-roost.co.uk/resources/lyx/PlottingGraphsInLyX.pdf
Does somebody know?

Wolfgang