Re: larger data set size

• To: John J Brecht <john.brecht@xxxxxxx>
• Subject: Re: larger data set size
• From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>
• Date: Fri, 31 Mar 2000 13:24:05 -0600

Hi John,

> > Usually our OutOfMemoryErrors come from Java3D, since it is
> > a real memory user (this is supposed to be improved in Java3D
> > version 1.2, but that is still in beta and we have not yet
> > modified VisAD to take advantage of its memory improvements).
> 
> i've been running into problems opening large datasets myself.  i'll get
> some error output together and send it in.
> 
> Something I've noticed, with regard to Java3D, that's particularly
> vexing is that it doesn't seem to to garbage disposal very effectively,
> if at all.  If I take one data set, and then start to visualize in
> different ways, more and more memory is steadily consumed, never to be
> made available again.  Is this just a WinNT issue, or is it the case on
> other platforms as well?  IS this something the new Java3D is supposed
> to fix?

Don Murray also found a memory leak in Java3D.  He and I
worked with the Java3D folks at Sun, and they acknowledge
the leak.  Its not clear when it will be fixed.

> along these same lines, i have a little app i wrote that reads ASCII
> data files, builds a VisAD data structure with the data and writes out
> netCDF files (for use with the SpreadSheet).  these netCDF files are
> signifigantly larger than the ASCII!  2.6 Mb of ASCII data becomes a 4.6
> Mb netCDF file.  is this expected, or is it likely i'm doing something
> wrong?

We'd have to see more details about the nature of the ASCII
data and the VisAD data object you build from it.

Cheers,
Bill
----------------------------------------------------------
Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738
http://www.ssec.wisc.edu/~billh/vis.html

• References:
  • larger data set size
    • From: Robert S Laramee
  • Re: larger data set size
    • From: Bill Hibbard
  • Re: larger data set size
    • From: John J Brecht