Adding ScalarMap to DisplayImpl gives DisplayException

• To: "'visad-list@xxxxxxxxxxxxx'" <visad-list@xxxxxxxxxxxxx>
• Subject: Adding ScalarMap to DisplayImpl gives DisplayException
• From: "Schlining, Brian" <brian@xxxxxxxxx>
• Date: Wed, 24 Oct 2001 15:30:03 -0700

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I'm trying to use VisAD for displaying locations of ships relative to an 
unmoored buoy (i.e a drifter). The drifter provides a center of reference for 
Lagrangian (not geographic) navigation.  The system is setup as a 
publish-sub**scribe system so that as new drifter or ships are deployed we can 
add their positions to the display dynamically. I've just started doing some 
testing with visAd but I've run into a problem.
 
First, I'm getting a visad.DisplayException. My steps for creating this 
exception start with the creation of a DisplayImpl. Then, I add  3 ScalarMaps 
and their associated DataReferenceImpl to the DisplayImpl  for the first 
drifter (one for the current location, one for the the drifters previous 10 
locations, and one containing a label identifying the current fix). Then I add 
the DisplayImpl to a JPanel and make it visible. So far so good... the point 
appears and is updated as the drifter moves about. The problem occurs when I 
try to add a second drifter. When I try displayImpl.addMap(someScalarMap) I get 
the following exception: visad.DisplayException: DisplayImpl.addMap: 
RendererVector must be empty. So it looks like once the display is up and going 
it doesn't like having additional data ScalarMaps added to it. Am I using the 
wrong approach? Any suggestions for a work around or different approach?
 
Thanks in advance
B
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Brian Schlining
Software Application Developer
Monterey Bay Aquarium Research Institute
brian@xxxxxxxxx
(831) 775-1855
http://www.mbari.org/~brian
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

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  • Re: Adding ScalarMap to DisplayImpl gives DisplayException
    • From: Steve Emmerson