Map projections

• To: "visad-list@xxxxxxxxxxxxx" <visad-list@xxxxxxxxxxxxx>
• Subject: Map projections
• From: Doug Lindholm <lind@xxxxxxxx>
• Date: Mon, 05 Mar 2001 11:45:38 -0700

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

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• Follow-Ups:
  • Re: Map projections
    • From: Don Murray
  • Re: Map projections
    • From: Doug Lindholm
  • Re: Map projections
    • From: Tom Whittaker