Hi Tia,
I'm not really sure why you are getting this effect, but my gut feeling
is that the data is making it draw that way. I don't know what your
parameters and data are, but I'd look at that if you aren't getting the
effect you want.
- Don
On Jul 27, 2004, at 10:49 AM, serrotam wrote:
> Thank you Don. Your dedication and attention to this mailing list is
> to be commended. Your advice has worked its charm every time.
> Thanks.
>
> For the record and other future newbie users, I have managed to create
> an overlay using a grid set of values that correspond to 3 different
> colors. Essentially I used the following:
>
> public class MyGridLayer extends Layer {
> :
> :
>
> OMGridData.Int rgbGridData = argb_GridData(someArrayOfIntVals);
> OMGrid omGrid = new OMGRID(lat_min, lon_min,
> deltaLat,
> deltaLon, rgbGridData );
> SimpleColorGenerator gen = new SimpleColorGenerator();
> omGrid.setGenerator(gen);
> this.omgraphics.addOMGraphic(omGrid);
> }
>
>
> This works well. I'll just have to optimize the color generator so
> that a new OMRaster is created only when the projection changes, and
> not everytime you pan or change position.
>
> QUESTION that remains. I did a checkered pattern (10x10 grid) to test
> this OMGrid and I notice that the cells on the edges of the checker
> board are essentially cut in half. I was wondering if you (or anyone
> else) could please explain this effect. I've attached a small image
> that illustrates what I'm seeing. Is this a function of how the
> generator places the pixels in the OMRaster ?
> tia
>
>
> Don Dietrick <dietrick_at_bbn.com> wrote:
> There's an OMGrid object that handles this situation. You create one
> where the grid should be overlayed, and give it an OMGridGenerator
> that
> creates OMGraphics from the data values within the grid. There are
> example OMGridGenerators in the package.
>
> I think you might want to check out the version from CVS, I did some
> work this year on OMGrids that might make it easier to use them for
> your data values. CVS instructions are on the website download page.
>
> There is more information about OMGrids in the javadocs.
>
> Regards,
>
> Don
>
> On Jul 8, 2004, at 5:02 PM, serrotam wrote:
>
> >
> > I would appreciate advice on how to approach the
> > rendering of a (2D)grid of values that need to be
> > rendered as an overlay on a lat-lon map.
> >
> > grid of values can be as large a 2000x2000 where
> > each value will correspond to a colored square of a
> > few kilometers each.
> > ____________________________
> > | red | yellow | green | ...
> >
> > | red | green | yellow | ...
> > | yellow | red | green | ...
> > | : | : | : | ...
> >
> > Which is the most efficient way of creating this
> > layer? I.e. with an OMRaster or OMPolygons?
> >
> > What are good examples for setting OMRaster
> > projections? these are still a bit confusing to me.
> > appreciate any hints.
> > TIA
> >
> >
> >
>
> Do you Yahoo!?
> Yahoo! Mail - 50x more storage than other providers!<omgrid-test.jpg>
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Don Dietrick, dietrick_at_bbn.com
BBN Technologies, Cambridge, MA
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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Received on Tue Jul 27 2004 - 14:30:43 EDT