Re: animation question & NullPointerException

Hi Curtis-

Curtis Rueden wrote:
When animating, the process is typically smooth for a few frames,
followed by one choppy frame, then smooth again, etc. When studying
VisBio's memory monitor, I noticed that these choppy frames correspond
to Java garbage collection operations. That is, the memory usage creeps
up by about 20MB per frame, then drops back down to previous levels
during the choppy frame.

My question is: can I fix this behavior, and if so, how? I realize that
this problem may be beyond the control of VisAD's display model, but I
thought I'd ask anyway to see if there are any thoughts or suggestions.

When we were doing some performance analysis in VisAD last year,
we found that a lot of the time was spent in garbage collection.
VisAD allocates a lot of float[][] arrays during transformations
and eventually, these have to get garbage collected.  Our
(Jeff's) enhancements tried to minimize these as much as possible,
but methods like adjustSeam() and adjustLongitude in VisADGeometryArray
classes still allocate a lot of memory which then gets collected.

I don't have any solutions, but thought I'd throw in my 2 cents.

don
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Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
"There's someone in my head, but it's not me"    Roger Waters
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