I started some notes here: - http://docs.codehaus.org/display/GEOTDOC/Referencing+Developers+Guide - http://docs.codehaus.org/display/GEOTDOC/1+Referencing+Configuration+and+Tool - http://docs.codehaus.org/display/GEOTDOC/3+Authorities+backed+by+the+EPSG+Database
You may also be interested in this recent proposal: - http://docs.codehaus.org/display/GEOTDOC/3+Authorities+backed+by+the+EPSG+Database It is worth using the visual tool to see what CRS Authorities you have configured. Enjoy, Jody > Jody, > > I just realized the GeoTools Javadoc already has told me where to > look. I think it is in the source code for the findMathTransform of > the CRS class. > > I'll check there. > > Still, any extra information is always helpful. > > SS > > On 9/4/07, Sunburned Surveyor <[EMAIL PROTECTED]> wrote: > >> Jody, >> >> I took a quick trip through the wiki for GeoTools Reprojection. It >> seems simple enough to use. >> >> However, I am one of those really sick people that needs to see how >> things work under the hood. Could you tell me where I would look in >> GeoTools to find out more about how the MathTransforms are calculated >> for the source and target CoordinateReferenceSystems. >> >> All I really know at this point is that you provide the GeoTools API >> with two ESPG codes and it "magically" returns a MathTransformation. >> >> What if I wanted to add support for a custom or new Map projection? >> What if there was a mistake in the generated MathTransformation that I >> wanted to fix? >> >> From the perspective of a "potential" maintainer it would be good to >> know how things are working at a lower level. I'm fairly familiar with >> geodetic calculations, so I'm not really scared of this (yet). >> >> I wonder if any of the GeoTools developers can give me a brief (two or >> three minute) overview of how GeoTools gets from two (2) ESPG codes to >> a MathTransform object. If I can get this overview I'll dig into the >> Javadoc and source code for more details. >> >> SS >> >> Thanks for indulging my curiousity. >> >> On 9/4/07, Sunburned Surveyor <[EMAIL PROTECTED]> wrote: >> >>> We had talked a little the other day about a incorporating third-party >>> reprojection code into OpenJUMP. I sent a post to the UDig list, since >>> I know they support "on-the-fly" reprojection. >>> >>> I know we don't necessarily want to mess with "on-the-fly" >>> reprojection in OpenJUMP, but maybe we couls use the reprojection code >>> from UDig for a stand-alone utility or for a OpenJUMP plug-in. >>> >>> Jody Garnett put a section on the wiki for us that talks about this: >>> >>> http://docs.codehaus.org/display/GEOTDOC/Welcome+to+JUMP+Developers >>> >>> The Sunburned Surveyor >>> >>> >>> >>> ---------- Forwarded message ---------- >>> From: Sunburned Surveyor <[EMAIL PROTECTED]> >>> Date: Sep 4, 2007 3:27 PM >>> Subject: Re: [udig-devel] Transformation/Reprojection >>> To: User-friendly Desktop Internet GIS <[EMAIL PROTECTED]> >>> >>> >>> Jody wrote: "Since this question is asked every couple of months by a >>> jump developer it has made its way into the geotools user guide..." >>> >>> I really apologize about that. I'm sure that I'm the jackass that >>> keeps asking the same question. UDig, GeoTools, GeoAPI, Kosmo, SIGLE, >>> SkyJUMP, DeeJUMP... >>> >>> I have a hardtime keeping track of it all sometimes. Please be patient with >>> me. >>> >>> The section you added to the wiki will be very helpful. I will look it >>> over and will also forward this message to the JPP Developer List. >>> >>> Thanks for all of your help. I look forward to trying out UDig on my >>> GIS project. :] >>> >>> SS >>> >>> >>> On 9/4/07, Jody Garnett <[EMAIL PROTECTED]> wrote: >>> >>>> Sunburned Surveyor wrote: >>>> >>>>> We were discussing options for reprojection/transformation code on the >>>>> OpenJUMP development list the other day. I know that UDig offers on >>>>> the fly reprojection, which is why I'm currently trying to download it >>>>> and get it running. >>>>> >>>>> I was curious, is the ,low-level reprojection code something UDig gets >>>>> from the GeoTools library, or is it code unique to UDig? Does the >>>>> low-level reprojection code work with GeoTools features, or does it >>>>> transform individual coordinates? Is it possible to access the API for >>>>> transformation of individual coordinates? >>>>> >>>>> >>>> It is from the GeoTools library; you can use the "referencing module" >>>> with out depending on any GeoTools feature stuff. It is suitable for >>>> OpenJUMP etc... >>>> >>>> Since this question is asked every couple of months by a jump developer >>>> it has made its way into the geotools user guide: >>>> - http://docs.codehaus.org/display/GEOTDOC/Welcome+to+JUMP+Developers >>>> >>>>> It seems to me that it would make sense to share reporojection code >>>>> between OpenJUMP and UDig, especially if we can transform individual >>>>> coordinate and don't need to deal with the feature model problem. >>>>> >>>>> >>>> Yes it makes sense to share; interfaces via geoapi and implementation >>>> via geotools, and hopfully swing widgets and swt widgets as well ;-) >>>> >>>> Don't worry about stealing worry about forking; if you see anything you >>>> want out of udig lets make sure we can place it in a common library so >>>> we can share maintence cost. >>>> >>>> Cheers, >>>> Jody >>>> _______________________________________________ >>>> User-friendly Desktop Internet GIS (uDig) >>>> http://udig.refractions.net >>>> http://lists.refractions.net/mailman/listinfo/udig-devel >>>> >>>> > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Geotools-devel mailing list > Geotools-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/geotools-devel > ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Geotools-devel mailing list Geotools-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
