What I want is to *not* draw lines between points, if the point is skipped. Previously I was using gnuplot, and would add a blank row in the input where I wanted the line to become disjoint; gnuplot would draw every point, with lines between all the points that didn't have a blank line between them.
I've put up an example of what I mean, here:
1) JFreechart. Notice cotinnuous yellow line at bottom:

2) Gnuplot: Notice noncontiguous brown line and points at bottom:

Any ideas?
Thanks!
Gary