> load("draw");
> draw2d( explicit( signum(x^3), x,-4,4, y,-2,+2) )
>   
Hello,
The correct syntax is
draw2d( explicit( signum(x^3), x,-4,4), yrange=[-2,2]);
The explicit object needs only the x-domain.
As Wolfgang mentioned, write
? explicit;
for more info.
Happy new year.
-- 
Mario Rodriguez Riotorto
www.biomates.net