How to plot a projective variety in Maxima?

>>>>> "Mario" == Mario Rodriguez <biomates at telefonica.net> writes:

    Mario> El vie, 12-04-2013 a las 13:44 +0300, Evgeniy Maevskiy escribi?:
    >> First off all we can try to eliminate one of the variables
    >> 
    >> eliminate([x*z-y^2=0,y*w-z^2=0,x*w-y*z=0],[w]);
    -> [z*(x*z-y^2),x*z-y^2]
    >> 


    Mario> With package 'draw' you can plot implicit and parametric surfaces. For
    Mario> example,

    Mario> load("draw") $
    Mario> s: eliminate([x*z-y^2=0,y*w-z^2=0,x*w-y*z=0],[w]);
    Mario> draw3d( implicit (first(s), x, -10, 10, y, -10, 10, z, -10, 10)  ) $

    Mario> More examples here:
    Mario> http://riotorto.users.sourceforge.net/gnuplot/implic

I think it would be really useful if maxima's info entry for draw
included a link to these examples.  I can never remember all of the
options and I can never remember where the examples are.

Ray