display of multiple data sets with frequent updates


I am trying to use VisAD to visualize the output of a groundwater transport
code. One of the displays that I want to implement shows histories, i.e.
concentrations of a species at one node of the mesh over time.

Swing controls allow to switch between different models (with completely
different data), and - within the selected model - between different nodes
and species. Simulated data are always present, observed data may be
present for some of the nodes and/or species. If observed data are present,
their display may be switched on or off by the user. The simulated data
should be displayed as a line, the observed data as points.

All these switches will be used a lot while this display is active, so the
response should be fairly rapid.

I have implemented some aspects I described above with a cell - whenever a
new node or species is chosen, doAction() will be called and the selected
simulated data are displayed. Now I want to add the display of the observed

First, is it more efficient to use a cell implementation with resampling or
should I do it like the SwitchDisplay example of the VisAD distribution?

Both simulated and observed data use the FunctionType (Time ->
Concentration), where the samples of the concentration are different for
every node and species. The observed data will typically have different
sample points for the time than the simulated data. Can I use the same
FunctionType for simulated and observed data, but different domains for the
time when I create the two FlatFields?

Can I use the same maps (time on x, concentration on y) for both types of
data with two different references or do I have to add another map for the
observed data, if they are to be displayed?

If no observed data are to be displayed, what is the best way to switch
this off? (remove the reference?)

How can I get the simulated data displayed as lines and the observed data
as points?

I hope I have described my problems well enough. Any hints are appreciated!

Thanks a lot in advance!

Hartmut Frenzel
Oak Ridge National Laboratory
Computer Science and Mathematics Division
Phone: (865) 241-0874
Fax: (865) 241-2850
E-mail: frenzelh@xxxxxxxx