newbie- can I make a bar graph?

Hi. I am new to VisAD but it seems really great. Problem is, it's so
powerful that I'm having trouble figuring out the simple stuff. I've
been looking at the (very helpful) tutorial at:

I want to do a plot similar to the one in example P2_03 or P2_04, but
insead of points to represent the data I would like bars. I want to make
a bar graph, where the bottom of each bar is at a certain point on the x
axis (in this example, maybe the midpoint of each bar would be at its
corresponding x value) and the top of each bar is at the height of the
corresponding y value. Do I have to make a VisADQuadArray for every bar
I want or is there a simpler solution? Does anybody have/know of a
simple Bar Chart example in 2d or 3d using VisAD?

Any help/suggestions are greatly appreciated.