Re: larger data set size

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.

Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738