I had the same problems with bursa wolf params for coordinate systems in Austria and this ended in parsing my own wkt defenitions. Afterwards, everything works fine.
Quoting Jean Marie <jm...@hotmail.fr>: > > Hi Jody > > I tried to debug from line : > > String code = CRS.lookupIdentifier( example, true ); // should be "EPSG:4230" > > and from > > CoordinateReferenceSystem crs = CRS.decode( code ); > > but I didn't come accross the method "equalsIgnoresMetadata" > although this method is visible several times in CRS.java ; > > if you are talking about a method equalsIgnoresMetadata inside of > CRS.java, I wonder from which method you get there ; > I must miss something... > > by the way I noticed that CRS.java has a main class that can display > the Bursa-Wolf parameters using parameter -bursawolfs > in a command line > > unfortunately for "EPSG:27572" no Bursa-Wolf parameter are displayed > (even if it requires gt-epsg-hsql-2.6.3.jar) ! > here is the result : > > ??????????????????????????????????????????????????? > ? Destination ? dx ? dy ? dz ? ex ? ey ? ez ? ppm ? > ??????????????????????????????????????????????????? > ??????????????????????????????????????????????????? > > in desperation, I took the Bursa-Wolf parameters from the > spatialreference.org site which gives a correct result, > namely TOWGS84[-168,-60,320,0,0,0,0] (and using only > gt-referencing-2.6.3.jar) > > If I can really get the parameters from the debug process it would > be reassuring > > thanks anyway > > Jean-Marie > > Subject: Re: [Geotools-devel] how to get Bursa-Wolf parameters in WKT strings > From: jody.garn...@gmail.com > Date: Mon, 17 May 2010 20:29:01 +1000 > CC: geotools-gt2-users@lists.sourceforge.net > To: jm...@hotmail.fr > > > > Hi Jean - we should keep this on the email list. > Can you try the code example and step through it with a debugger? > This should help explain why it will hep you.1. You parse the WKT > into a CoordinateReferenceSystem2. You look for a matching > CoordinateReferenceSystem coming out of the official EPSG database > Inside that code it goes through and checks for a > CoordinateReferenceSystem with the same values as yours; ignoring > the metadata (such as name and description). The method is called > "equalsIgnoresMetadata" if you are interested.3. It returns you a > match ... and that match includes Bursa Wolf Parameters > Jody > On 17/05/2010, at 7:37 PM, Jean Marie wrote:Hi jody > > I had a look at the example given at : > > http://docs.codehaus.org/display/GEOTDOC/01+CRS+Helper+Class#01CRSHelperClass-SearchingforaCoordinateReferenceSystem > > I think you refer to the following code : > ----- > String code = CRS.lookupIdentifier( example, true ); // should be > "EPSG:4230"CoordinateReferenceSystem crs = CRS.decode( code ); > ------ > > well I don't know how this can help me ; > > you talked also about an "Equals" method that could assist me ; > well I don't see how > > if you could give me some further details it would be helpfull > as I don't know how to sort out this problem of String WKT > which sometimes contains all parameters required and sometimes doesn't > > thanks a lot > > Jean-Marie > > > Subject: Re: [Geotools-devel] how to get Bursa-Wolf parameters in WKT strings > From: jody.garn...@gmail.com > Date: Thu, 13 May 2010 08:35:11 +1000 > CC: geotools-de...@lists.sourceforge.net > To: jm...@hotmail.fr > > Hi Jean > Here is what I kind of do; I use the CoordinateReferenceSystem > created my WKT to look up the "Real" CoordinateReferenceSystem > produced by the EPSG database (which is much more complete). > There is an "Equals" method that ignores metadata to assist you with > this; and because I find CoordinateReferenceSystem stuff difficult > to manage by hand there should be a helper method ... > Yes there is - indeed it is one of the use-cases covered by the user > > guide:-http://docs.codehaus.org/display/GEOTDOC/01+CRS+Helper+Class#01CRSHelperClass-SearchingforaCoordinateReferenceSystem > Cheers, Jody > On 13/05/2010, at 3:15 AM, Jean Marie wrote:Hello > > my purpose is to get a list of projection systems described in a WKT > format (so using gt-epsg-hsql-2.6.3) ; > and then to use these WKT representations to achieve tranformations > using only > the library gt-referencing-2.6.3.jar > > to get these WKT strings I use the following code : > > CoordinateReferenceSystem crsSrc = > ReferencingFactoryFinder.getCRSAuthorityFactory("EPSG", > null).createCoordinateReferenceSystem(EPSG); > and then crsSrc.toWKT() gives the WKT specification for EPSG > > I took 3 WKT representations for respectively EPSG = "EPSG:4326", > EPSG = "EPSG:2056" and EPSG = "EPSG:27572" > then I created for each one a CoordinateOperationFactory object to > carry out 2 transformations : > one from 4326 to 2056 (Switzerland) et the other from 4326 to 27572 > (France) using the WKT strings > > I noticed that the WGS84 to Swiss transformation is correct, > while the WGS84 to French transformation generates an error saying > that Bursa-Wolf parameters are required ; > > I would like to know how to sort out this problem as I need accurate results > and I cannot afford to use the following code involving some > transformation errors: > > CRS.findMathTransform(crsSrc, crsDest, true) > > is it possible to get Bursa-Wolf parameters in each WKT representation ? > > thanks a lot > > Jean-Marie > > Vous voulez protéger votre vie privée ? 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