In the J session, see the demo Studio|Demos...|plot. In the demo, use Options|View Definition to view and experiment with the plot definitions.
As from scripts 6.02.041, these demos can be run interactively, in particular this is useful in Jconsole. Try:
J6
load '~system/examples/graphics/plot/plotdemos.ijs' plotdemos 4 NB. argument is demo number in range 0-54
J7 requires installation of the package demos/plot via Pacman
load '~Demos/plot/plotdemos.ijs' plotdemos 4 NB. argument is demo number in range 0-54
Some examples in the wiki: