kml question

[Bernd Becker]

Hm.

You need all of the following instructions
ga-> c
ga-> set parea 0 11 0 8.5
ga-> set mpdraw off
ga-> set mproj scaled
ga-> set grid off
grid is off
ga-> set grads off
     set frame off
ga-> d tmean

Or fail to suppress the outer black line of the plot.

In google earth, finally there appears a black bar where the eastern
most
longitude meets the western most longitude.

You can  suppress a frame to be produced in grads
setting frame "off".

Regards,
Bernd.


On Thu, 2009-02-19 at 09:32 -0500, Jennifer Adams wrote:
>
>
> On Feb 18, 2009, at 10:02 PM, Arlindo da Silva wrote:
> > Jennifer, Brian:
> >
> >
> >   The new kml option is very cool. Do you have any plans to support
> > PNG with "set gxout kml"?  TIFF is proprietary, and have not had a
> > major upgrade since 1992. Do you know how well it supports
> > transparency?  (Very important for combining layers on GoogleEarth.)
> > You could probably reuse most of the printim code for a PNG
> > option. Just curious.
> >
> > --
> > Arlindo da Silva
> > dasilva at alum.mit.edu
> >
>
>
> Hi, Arlindo --
> I have cc'd gradsusr on this question, since I think it is of general
> interest.
>
> The image files created with 'gxout geotiff' and 'gxout kml' are
> roughly equivalent to the display inside the plot area of 'gxout
> grfill' -- a grid of pixels without anything else. So, if you issue
> the following commands:
> 'set parea 0 11 0 8.5'
> 'set grid off'
> 'set mproj scaled'
> 'set x 0.5 720.5'
> 'set y 0.5 381.5'
> 'set mpdraw off'
> 'set grads off'
> 'd variable'
> 'printim x720 y381'
>
>
> Then you would create a PNG that is roughly equivalent to the TIFF and
> you could substitute that file name in the KML and it would work just
> as well. In some way, this technique is more flexible because you can
> use shaded contours, overlay vectors, etc. and still draw them on
> Google Earth.
>
>
> The TIFF file created with 'gxout kml' has the same geolocation
> metadata embedded in it the way the 'gxout geotiff' output does. The
> difference is that the 'gxout geotiff' files have floating-point data
> values for each pixel and the 'gxout kml' files have color-numbered
> index values. I assume there are some GIS applications that would only
> need the image and not the data, so that's why I set up a way to
> create both. The KML provides a handy way to look at the images with
> Google Earth.
>
>
> For testing, I have been using a free program called Quantum GIS
> (qgis.org). Transparency is pretty easy to control within this
> application -- you can set any number of pixel values to be
> transparent (on a scale of 0-100%). I think Google Earth has some
> controls for transparency too. So far, I haven't seen a need to set up
> transparency in the GrADS geotiff output. And it's definitely not
> clear to me that if I put a transparency mask in the TIFF file, the
> GIS applications will know what to do with it. But I'm still a GIS
> neophyte...
>
>
> Please note that some problems with the 'gxout geotiff' output have
> been reported to me. I am doing some re-coding and testing and may
> have some patches and/or an updated version soon.
>
>
> Jennifer
>
>
> p.s. Hooray for TIFF for keeping the standard consistent for all these
> years. We need more standards like that.
>
>
>
>
>
>
> --
> Jennifer M. Adams
> IGES/COLA
> 4041 Powder Mill Road, Suite 302
> Calverton, MD 20705
> jma at cola.iges.org
>
>
>
>
>
>
--
Bernd Becker   The Monthly Outlook
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