Re: LinearLatLonSet

Hi John,

This image is what I'd expect, assuming your are a DisplayImplJ2D.
Your longitude bounds of -180 to +108 leave to large a gap (72
degrees) for any interpolation. And you won't see interpolation
in a simple display like this. You will see interpolation ith a
gap that is comensurate with the spacing in your grid, and you
cal the resample() method of your Field with a Set that crosses
the 180 boundary. Frankly, the situation where LinearLatLonSet
is needed does not arise very often (which is why we don't have
any examples).

Cheers,
Bill

On Wed, 14 Jul 2004, John C Cartwright wrote:

> Thanks for your prompt reply, Bill.  I modified the code to change the
> longitude range and disable the texture mapping.  The results are still
> not what I expect. Can you shed any light on what I'm doing wrong?
>
>      latitude = RealType.Latitude;
>      longitude = RealType.Longitude;
>      domain_tuple = new RealTupleType(latitude, longitude);
>
>      int NCOLS = 5;
>      int NROWS = 6;
>
>      domain_set = new LinearLatLonSet(domain_tuple, -90.0, 90.0, NROWS,
>                                              -180, 108.0, NCOLS);
>      dispGMC.setTextureEnable(false);
>
>
> -- john
>
>
> Bill Hibbard wrote:
> > Hi John,
> >
> > The image attached to your email is displayed using texture
> > mapping, so interpolation is not used. Also, your lower and
> > upper longitude bounds (-180 and +180) are "equal", so there
> > would be no meaningful interpolation between them anyway.
> > LinearLatLonSet is only useful if your application is using
> > interpolation and you have a truly "circular" longitude
> > sampling (say every 5 degrees from -177.5 to +177.5). Sorry
> > to say I don't know of an example using LinearLatLonSet.
> >
> > Good luck,
> > Bill
> >
> > On Wed, 14 Jul 2004, John C Cartwright wrote:
> >
> >
> >>Hello All,
> >>
> >>I'm trying to employ the LinearLatLonSet to take advantage of the
> >>longitude "wrapping".  Can someone provide me an example of how to
> >>properly use this?  Although I can get an image, it's not clear to me
> >>that any interpolation is occurring across the longitude boundary. Test
> >>case is based on example P3_2 in the tutorial and salient parts of the
> >>code are listed below.
> >>
> >>
> >>     int NCOLS = 5;
> >>     int NROWS = 6;
> >>
> >>     latitude = RealType.Latitude;
> >>     longitude = RealType.Longitude;
> >>     domain_tuple = new RealTupleType(latitude, longitude);
> >>
> >>     domain_set = new LinearLatLonSet(domain_tuple, -90.0, 90.0, NROWS,
> >>                                           -180, 180.0, NCOLS);
> >>
> >>
> >>
> >>Thanks for your help!
> >>
> >>-- john
> >>
> >>====================================================
> >>John Cartwright
> >>Associate Scientist
> >>Geospatial Data Services Group
> >>CIRES, National Geophysical Data Center/NOAA
> >>(303) 497-6284
> >>John.C.Cartwright@xxxxxxxx
> >>====================================================
> >>
> >>
> >
> >
>
>
> --
> ====================================================
> John Cartwright
> Associate Scientist
> Geospatial Data Services Group
> CIRES, National Geophysical Data Center/NOAA
> (303) 497-6284
> John.C.Cartwright@xxxxxxxx
> ====================================================
>
>