MAPLE does not have the capability of plotting nice (say, round) FILLED IN points,
and "hollow" points are very often hard to distinguish in a window cluttered with graphs. I pointed this out to the Maple Support Team, and the following roundabout was suggested:
> c := disk([9,1.5], .2, color=black):
> d := disk([2,2.8], .2, color=black):
> display(p1, p2, p3, p4, p5, p6,c, d,
> display(p1, p2, p3, p4, p5, p6,c, d,view=[-1..10,0..4]);
However, the BIG inconvenient of this roundabout is that in reality it plots little circles. So, if the scales in both axes is strongly different (think of plotting monthly salaries, in dollars, against time, in months) you don't get round points, but very flat ellipses.
When I pointed out this shortcoming, the Support Team promised to pass this suggestion to the Maple Developing Team, as a feature to add in further Maple upgrades. Unfortunately, this was way back when Maple 5 was around. We are now down to Maple 10, and still no filled-in points in view!
Is this really so hard to implement? It makes me wonder, because other computer algebra systems, such as Mathematica, have this even as the default option when you choose to plot points.
An addition of filled-in points as options for plotting points would be very welcome.