[R] "biplot" graphical options?

[Jari Oksanen]

Manca Marco (PATH <m.manca <at> path.unimaas.nl> writes:
. 
> I am struggling in the attempt to impose some graphical conditions (changing
point symbols, colors, etc)
> to biplot function (I am using it to visualize the results of princomp) but I
can't apparently manage to
> change anything but the axis... and I have been browsing manuals and vignettes
without finding any
> explicit suggestions on how to operate...
> 
> Can anyone, please, point my attention to the relevant documentation?

Howdy,

The relevant documentation in this case is ?biplot. The documentation to the
specific method is less useful (?biplot.princomp). That documentation tells you
that you can't do what you want to do. No choice. For instance, col (for colour)
can be of length 2 giving different colours for each set of points, but you
cannot vary the colour within the set. Further, you cannot turn off using arrows
and text or even suppress the plotting and add your own points. 

If you use RSiteSearch("biplot"), you can find some packages with more
flexibility than stats:::biplot.princomp and stats:::biplot.default. Another
alternative is to write your own biplot function or do the plot by hand using
the basic commands.

Best wishes, Jari Oksanen