Re: Masking data

Hi Cicero,

The best way to eliminate the "Data is null" warnings is to
call DataRenderer.suppressExceptions(true) on the DataRenderer
with null data.  In your case, one way to do this would be to
put something like:

    Vector renderers = display.getRendererVector();
    int size = renderers.size();
    for (int i=0; i<size; i++) {
      DataRenderer r = (DataRenderer) renderers.elementAt(i);

after your display setup code.


At 01:41 PM 4/24/2002, Cicero A. W. Zandoná wrote:
>Hi Curtis and everybody
>I didn´t know about the ResSwitch class till now (maybe I need to explore 
>VisAD more). But it came in great time to solve the performance issues I´m 
>facing. Thank you.
>But there is a little problem:
>The class worked very well with 2D radar data, but when I tried with map data 
>the behavior was different:
>When the display is busy, the maps disapear. Maybe its obvious, since their 
>Reference contais an UnionSet and not a FieldImpl. But this is not the 
>problem, its good this way (an ultimate reduction). The problem is the "Data 
>is null" warnings appearing in the display.
>If there is some way to set them off, please answer.
>Thanks already Cicero A. W. Zandoná.
>Curtis Rueden wrote:
>>Hi Renaud,
>>We've implemented some "resolution switching" logic that enables
>>a display to automatically downgrade its displayed data when
>>the user is actively manipulating it.  When the display sits idle
>>for a second or two, the full-resolution version of the data gets
>>swapped back in.
>>Run "java visad.util.ResSwitcher data" where "data" is the name
>>of a data file you'd like to see displayed.
>>See visad/util/'s main() method to see how to
>>link a ResSwitcher object to your display.  I'm curious to hear
>>how well it improves performance of your large 3-D cloud data.
>>At 03:05 AM 4/23/2002, you wrote:
>>>Hello, I'm displaying a cloud through a 3D display: something like ( index 
>>>-> (x,y,z,color) ) in Visad notation. 
>>>When you have more than 20000 vertices displayed , operations like rescaling 
>>>an axis are very slow. To deal with this issue, I had the idea to mask some 
>>>vertices. For example, with 50000 vertices, I would temporarily (during the 
>>>rescaling operation) display  only 1 out of 4 vertices. Does someone know an 
>>>efficient way to do that, i.e. without removing the reference data, and 
>>>creating a new one with only 12500 vertices ? Thanks by advance. 
>>>Renaud DAÏAN