Re: Map projections

• To: "visad-list@xxxxxxxxxxxxx" <visad-list@xxxxxxxxxxxxx>
• Subject: Re: Map projections
• From: Doug Lindholm <lind@xxxxxxxx>
• Date: Mon, 05 Mar 2001 13:44:10 -0700

Doh! I found the problem and it was me. I defined my new set as a
Gridded2DSet with manifold dimension = ONE instead of TWO. As a result,
VisAD did exactly as I told it and plotted the data along a line.
Everything works now!

Hopefully I'm not the only one that learned something from this.

Thanks,
Doug

Doug Lindholm wrote:
> 
> Hi,
> 
> I've attempted what I thought was the quick and dirty solution to my
> Lambert map projection problem given my limited understanding of
> visad.CoordinateSystem. My attempts to use
> visad.data.hdfeos.LambertConformalConic in a way similar to
> PolarCoordinateSystem in Test11 was not fruitful so I took the following
> approach:
> 
> construct my terrain field: (lon,lat) -> alt
> 
> construct a visad.data.hdfeos.LambertConformalConic
> 
> extract the samples of my domain set and run them through
> LambertConformalConic.fromReference() thus creating a new domain set of
> (x,y).
> 
> construct a field on this new set assigning the original alt values.
> 
> display mapping x and y to the Axes.
> 
> The results are promising - it looks like a Lambert projection, but the
> rendering is flakey. I've linked a "before" and "after" image.
> 
> ftp://ftp.rap.ucar.edu/incoming/lam1.gif
> ftp://ftp.rap.ucar.edu/incoming/lam2.gif
> 
> Is there something fundamentally wrong with what I'm trying to do or is
> there a bug in the transform or the rendering?
> 
> I'll throw together some sample code if it helps.
> 
> Thanks,
> Doug
> 
> --
> *----------------------------------------------------------------------*
> | Doug Lindholm, Software Engineer          |  E-mail: lind@xxxxxxxx   |
> | Research Applications Program             |   Phone: 303-497-8374    |
> | National Center for Atmospheric Research  |                          |
> | P.O. Box 3000                             |     There's no place     |
> | Boulder, Colorado 80307-3000              |        like $HOME        |
> *----------------------------------------------------------------------*

-- 
*----------------------------------------------------------------------*
| Doug Lindholm, Software Engineer          |  E-mail: lind@xxxxxxxx   |
| Research Applications Program             |   Phone: 303-497-8374    |
| National Center for Atmospheric Research  |                          |
| P.O. Box 3000                             |     There's no place     |
| Boulder, Colorado 80307-3000              |        like $HOME        |
*----------------------------------------------------------------------*

• References:
  • Map projections
    • From: Doug Lindholm