Hello Jody,

I found part of the problem: the postgis definition of 3395 contains

"  PARAMETER["latitude_of_origin",0],"

in the srtext.  Removing this makes it recognizable in uDig.

Thanks,
David

On Thu, Feb 12, 2009 at 3:15 PM, Jody Garnett <[email protected]>wrote:

> David Zwarg wrote:
>
>> Hi Jody,
>>
>> Thanks for the response.
>>
>> I am having difficulty adding my own SRID, and getting uDig to recognize
>> it.  What I really want is to be able to support this in my own custom
>> application, but for now, I am running uDig from Eclipse -- I don't know if
>> that changes things.
>>
>> This is what I've done: I created a geometry table in PostGIS, and set the
>> SRID to 3395 (the SRID in PostGIS for "WGS 84 / World Mercator").  When I
>> load the layer into uDig, the CRS is set to 4326.  That didn't work.
>>
> When you right click on the layer (or better yet go to the catalog and find
> the table) and ask for more information what does it tell you? The GeoTools
> library we use does go and check the WKT definition from postgis.
>
> The definition of 4326 may match what you were trying to set up?
>
>> Next, I created a geometry table in PostGIS, and set the SRID to 41001
>> (the SRID in uDig for "WGS84 / Simple Mercator" -- this is nearly the same,
>> and would suit my purposes if it would work).  When I load the layer into
>> uDig, the CRS is set to 4326.
>>
> For any definition that is not complete (say from a shapefile or something)
> we try and look up the offical EPSG definition and find a match; could this
> be what is happening to you?
>
>> I assumed that the problem was that PostGIS and uDig had to have the same
>> CRS in both their systems, so the SRID in the PostGIS spatial_ref_sys table
>> matches the EPSG code in uDig's Coordinate System dialog.  Sure enough, if I
>> set the PostGIS spatial reference to something else (for my test, I used
>> EPSG:4269), then when it loads into uDig, the CRS is set correctly.
>>
>> Additionally, when I attempt to add the definition from PostGIS (the
>> srtext from the spatial_ref_sys table) for 3395 into the Custom CRS box in
>> uDig, I can press "Apply" and "OK" to my heart's content, but the dialog
>> never closes, and I can't get out of the dialog without canceling.
>>
>
> The custom CRS dialog box is just consulting uDig internal list of
> definitions; there are facilities for you to add more definitions to uDig at
> a coding level (you can set up a little property file with additional
> definitions). Before we go that far ... can you compare what you are trying
> to do with the definition of 4326?
>
>>
>> Please advise,
>> David
>>
>>
>> On Wed, Feb 11, 2009 at 6:42 PM, Jody Garnett <[email protected]<mailto:
>> [email protected]>> wrote:
>>
>>    Mark Leslie is the postgis guy I know these days and he can
>>    confirm or deny what I say here :-)
>>
>>    You can add your own SRID codes to to PostGIS and define one th be
>>    generic cartesian 2D if you like. UDig will pick up this WKT
>>    definition and be fairly happy.
>>
>>    In uDig you click to change the projection; there are two tabs
>>    (one where you select the formal epsg definition from a list; and
>>    a second where you can type in your own WKT). You can also right
>>    lick on a layer and "force" a change of projection (if the data
>>    source is wrong for example - it does happen).
>>
>>    Mercator is supported in our referencing library so you should be
>>    able to proceed resonably well. Normally PostGIS SRID codes line
>>    up with the EPSG codes ...
>>
>>    Jody
>>
>>    David Zwarg wrote:
>>
>>        Hello,
>>
>>        I am wondering if there is a way to use the World Mercator
>>        projection in PostGIS in uDig.  I am unable to use either the
>>        PostGIS (3395) or the uDig (41001) EPSG codes for world
>>        mercator in my PostGIS layer -- they both show up as Generic
>>        cartesian 2D.  As soon as I attempt to add geometry and edit
>>        geometry, uDig goes into an endless loop of
>>        IllegalArgumentExceptions.
>>
>>        However, if I use an EPSG code that appears in BOTH postgis
>>        and uDig, it seems to work alright.  If there was a way to
>>        represent Generic cartesian coordinates in PostGIS, that would
>>        be preferable, but -1 causes this same
>>        IllegalArgumentException spiral.  Am I missing a general
>>        projection that would be more suitable?
>>
>>        Also, during this experiment, I was unable to create a custom
>>        CRS in the uDig map preferences, or by clicking on the button
>>        in the status bar.  How do you create a custom CRS from a
>>        known WKT?
>>
>>        Thanks,
>>        David
>>
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>>        http://udig.refractions.net
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>>
>>
>>    _______________________________________________
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>>    http://udig.refractions.net
>>    http://lists.refractions.net/mailman/listinfo/udig-devel
>>
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
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>> http://udig.refractions.net
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>>
>>
>
> _______________________________________________
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> http://udig.refractions.net
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