On 19/05/2010, at 12:18 AM, Jean Marie wrote:
> Thanks Jody for your suggestion
Did the code example on that page work for you?
> at present, I just need a dozen of WKT strings but I already notice that,
> sometimes , it is hard to find the Bursa-Wolf parameters ; as I told
> you is that I must use a light library (gt-referencing-2.6.3.jar)
And I always remind you gt-referencing does not do anything on its own :-) You
need to feed i some definitions as well ... but I understand you do not want to
use a database.
> for example if I consider Spain mainland the corresponding EPSG code is 2062
> and there is no TOWGS84 parameters in the WKT string ;
> http://spatialreference.org/ref/epsg/2062/ doesn't specify any TOWGS84[..]
> string as well
>
> as Geotools requires Bursa-Wolf parameters to work (when using just
> gt-referencing-2.6.3.jar), is there an official site providing them?
The EPSG database is the official site (http://www.epsg.org/) who distribute
their data in an Access database. Sometimes individual countries also provide
official definitions as well). We set up GeoTools so you can configure it as
needed for your data.
> if they are not required, is there a "trick" to set TOWGS84[..] to default
> values ?
I am afraid all these numbers mean something and should be defined by a
standards agency (as they represent an agreement between map makers).
> note : even when using gt-epsg-hsql-2.6.3.jar I have an error at :
> op = coFactory.createOperation(crsSrc, crsDest); // crsSrc created from the
> WKT string (4326), crsDest created from the WKT string (2062) saying that
> Bursa-Wolf parameters are required...
>
> I have another remark regarding the WKT format :
> if I use the OGC wkt definitions given by the site spatialreference.org with
> Geotools, none of them works fine (at least those I tried) ; the results are
> wrong (even if I invert latitude and longitude...)
> does it mean that the WKT format depends on the tools that processes it ?
>
Not sure about that; there are many flavours of WKT (mostly it is organisations
like Oracle that modify things a bit). There is a specific osgeo org mailing
list on this topic (making sure the coordinate reference systems work well
between projects).
Jody
------------------------------------------------------------------------------
_______________________________________________
Geotools-gt2-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
