Re: [udig-users] WGS84 problem

[andrea antonello <andrea.antonello@xxxxxxxxx>]

Still I am not convinced Jody. In my understanding a geographic
reference system lives in the ellipsoid space. Therefore it doesn't
make sense to build it with coordinates that get outside +-180, +-90.
If we are talking about projected systems, ok, you do whatever you
want, but not in the geographic space.
So, I guess there is no way to handle that in the prj file.

Jody, isn't there a way to use some style geometry function to apply a
transform to the geometry?

Andrea


On Thu, Sep 8, 2011 at 11:24 PM, Jody Garnett <jody.garnett@xxxxxxxxx> wrote:
> The correct solution here is to define a custom CRS that actually matches
> the data; the uDig environment has the tools to do this; what is needed is a
> bit of research / reading.
> I do not think there is a need to look functions; the data is *correct* - we
> just need to have the proper description so that uDig can use it.
> Did you want to mess with the unit setting a bit? I do not have any sample
> data so I feel a bit like I am making suggestions from the side line.
> There is some scary background reading
> here: http://docs.geotools.org/latest/userguide/library/referencing/internal.html
> But really all the same settings are available from WKT; it would be easier
> to read the standard or ask the person who gave you the data for the correct
> WTK (or ".prj" file).
> --
> Jody Garnett
>
> On Thursday, 8 September 2011 at 9:39 PM, andrea antonello wrote:
>
> While scaling a projected system might be useful, I don't think that
> it makes much (physical) sense to scale a geographic coordinate
> system.
> So I assume there is no way to scale the WGS84 system (but I might be
> wrong) from the projection definition.
>
> Perhaps through the new sld functions that geotools added lately? But
> I would not know how. Jody?
>
> Ciao,
> Andrea
>
>
>
> On Wed, Sep 7, 2011 at 2:13 PM, Jody Garnett <jody.garnett@xxxxxxxxx> wrote:
>
> You can define your own custom "CRS" for the layer.
> 1. right click on the layer (after you have loaded it)
> 2. choose the CRS property page
> 3. select a good normal WGS84 starting point (such as "EPSG:4326") it should
> look something like this:
> GEOGCS["WGS 84",
>   DATUM["World Geodetic System 1984",
>     SPHEROID["WGS 84", 6378137.0, 298.257223563, AUTHORITY["EPSG","7030"]],
>     AUTHORITY["EPSG","6326"]],
>   PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]],
>   UNIT["degree", 0.017453292519943295],
>   AXIS["Geodetic longitude", EAST],
>   AXIS["Geodetic latitude", NORTH],
>   AUTHORITY["EPSG","4326"]]
> 4. Switch to the tab that lets you define your own
> 5. Modify the "well known text" description so that the axis information is
> different (and matches your data)
> I hunted down some examples for you here:
> - http://docs.geoserver.org/latest/en/user/advanced/crshandling/customcrs.html
> it looks like the "scale factor" may actually just allow you to do what you
> want? The "Well known text" is actually a standard defined by the OGC - so
> if you really get stuck you can read the standard?
> --
> Jody Garnett
>
> On Wednesday, 7 September 2011 at 5:38 PM, Mirza Hadzic wrote:
>
> Hello, I have problem with dataset (MySQL) which is stored in integer WGS84
> coords, so it is multiplied by 1 million. For example coordinate 24.002525
> is stored as 24002525 (same rule for both coords). Is there any magic in
> uDig to display this?
> _______________________________________________
> udig-users mailing list
> udig-users@xxxxxxxxxxxxxxxxxxxxx
> http://lists.refractions.net/mailman/listinfo/udig-users
>
>
> _______________________________________________
> udig-users mailing list
> udig-users@xxxxxxxxxxxxxxxxxxxxx
> http://lists.refractions.net/mailman/listinfo/udig-users
>
>