tom
bingo!
works great...the image loads super-quick and looks good (no more
triangles)...thanks so much for the help!
jc
> -----Original Message-----
> From: Tom Whittaker [mailto:tomw@xxxxxxxxxxxxx]
> Sent: Tuesday, January 06, 2004 3:33 PM
> To: Jim Cookas
> Cc: Jim Koutsovasilis; visad@xxxxxxxxxxxxxxxx
> Subject: Re: slow 2d image generation
>
>
> Hi Jim...
>
> Sorry, I missed typed last night. You should use parentheses
> for the range
> values. The square brackets are used for options [units,
> miss, etc]. See
> section IIIb of the README.text file.
>
> Please let me know if you have any more problems with this.
> (Especially since
> I always use comma-separated values... ;-)
>
> tom
>
>
> Jim Cookas wrote:
>
> > tom, all
> >
> > thanks a ton for the suggestion...it looks like this will
> be the method of choice for speeding up image display...i
> implemented the changes today, but i'm having a problem
> getting the image to display...i think it is a problem with
> my ascii file format...
> >
> > i am using tab-spaced values...here is what test.tsv looks like:
> >
> >
> > (Down_Range,Cross_Range)->(RCS)
> > Down_Range[-755.383:755.383]
> Cross_Range[-755.383:755.383] RCS
> > [ 256 RCS values for Down_Range #0 ]
> > [ 256 RCS values for Down_Range #1 ]
> > .
> > .
> > .
> > [ 256 RCS values for Down_Range #255 ]
> >
> >
> > when i try to load this file into visad, i get these
> messages at the terminal:
> >
> >
> > Unit name problem:visad.data.units.ParseException: negative
> sign follows decimal point with -755.383:755.383
> > Unit name problem:visad.data.units.ParseException: negative
> sign follows decimal point with -755.383:755.383
> >
> >
> > any ideas on the problem?...thanks again!!
> >
> > jc
> >
> >
> >>-----Original Message-----
> >>From: Tom Whittaker [mailto:tomw@xxxxxxxxxxxxx]
> >>Sent: Monday, January 05, 2004 9:43 PM
> >>To: Jim Cookas
> >>Cc: Jim Koutsovasilis; visad@xxxxxxxxxxxxxxxx
> >>Subject: Re: slow 2d image generation
> >>
> >>
> >>Jim:
> >>
> >>I believe that part of the slowness in "reading" is that
> the form of
> >>your data is producing an IrregularSet, which VisAD needs to
> >>"triagulate" when it does the display. If your data points are a
> >>"regular grid" (meaning, regular/constant spacing between
> >>data points)
> >>you can use the format:
> >>
> >>Down_Range[-755.383:-200], Cross_Range[-755.838:-500], RCS
> >>
> >>(where the '-200' and '-500' should be the actual ending
> >>values for the
> >>sample domain. If you do this, and then put all the RCS
> >>values (along
> >>the Cross_Range)for a single Down_Range on one input line.
> The text
> >>reader will compute the actual domain sampling coordinate for
> >>each "RCS"
> >>value. When you do this, the TextAdapter will make a
> >>Gridded2DSet for
> >>the sampling domain, and it is handled faster than the IrregularSet.
> >>
> >>Of course, there will be some overhead for reading and
> >>decoding the text
> >>in either case, so I agree with JimK -- you may want to
> >>create your own
> >>reader.
> >>
> >>tom
> >
> >
>
> --
> Tom Whittaker (tomw@xxxxxxxxxxxxx)
> University of Wisconsin-Madison
> Space Science and Engineering Center
> Cooperative Institute for Meteorological Satellite Studies
> Phone/VoiceMail: 608.262.2759
>
>
