Paul Austin a écrit : >Michael, > >I agree with all you said. I guess my statement there was regarding a >particular type of CoordinateOperation. > > So we are on the same page as Landon said ;-)
>Paul > >Michaël Michaud wrote: > > >>Paul Austin a écrit : >> >> >> >> >>>Landon, >>> >>>Agreed each CoordinateOperation class should only know how to go in >>>either the direction Geographics->ProjectedSystem or >>>ProjectedSystem->Geographics. It should not need to know about any other >>>systems. >>> >>> >>> >>> >>> >>Coordinate operations are not just Geographics->Projected and >>Projected->Geographics. This is only the projection part (first and last >>operation of Stefan's transformation chain). >>Many operations involve a datum change. When you go from a local datum >>to wgs84 for example, you must consider that the new coordinate system >>has another origin, another orientation, and the ellipsoid you will use >>to calculate lon and lat has another shape ! This transformation has no >>common point with a projection, but most people do not differentiate >>both operations. >>If you want to apply the pivot principle, you have to say : each >>CoordinateReferenceSystem has to know how to go from and to Geocentric >>WGS84, but again, it may be much calculations for cases where only one >>local datum is involved. >> >>Michael >> >> >> >> >>>Paul >>> >>>Sunburned Surveyor wrote: >>> >>> >>> >>> >>> >>>>Paul wrote: "My vision for end user code. >>>> >>>>JtsTransform transform = >>>>JtsTransformFactory.createCoordinateConversion(3005, 26910);" >>>> >>>>I like it! >>>> >>>>My concerns are about how the layer underneath this works. I think a >>>>system where the steps necessary for the transformation are left to >>>>the implementer of a projection and not the code provided with the "to >>>>and from" spatial reference systems is the best. >>>> >>>>Here is another way of saying it: In an ideal system the code >>>>performing the actual transformation should have no idea of what the >>>>eventual destination spatial reference system is. It should only need >>>>to know how to get a coordinate from itself to the pivot spatial >>>>reference system. >>>> >>>>SS >>>> >>>>On 9/10/07, Paul Austin <[EMAIL PROTECTED]> wrote: >>>> >>>> >>>> >>>> >>>> >>>> >>>>>Landon, >>>>> >>>>>My vision for end user code. >>>>> >>>>>JtsTransform transform = >>>>>JtsTransformFactory.createCoordinateConversion(3005, 26910); >>>>> >>>>>Paul >>>>> >>>>>------------------------------------------------------------------------- >>>>>This SF.net email is sponsored by: Microsoft >>>>>Defy all challenges. Microsoft(R) Visual Studio 2005. >>>>>http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ >>>>>_______________________________________________ >>>>>Jump-pilot-devel mailing list >>>>>Jump-pilot-devel@lists.sourceforge.net >>>>>https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>------------------------------------------------------------------------- >>>>This SF.net email is sponsored by: Microsoft >>>>Defy all challenges. Microsoft(R) Visual Studio 2005. >>>>http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ >>>>_______________________________________________ >>>>Jump-pilot-devel mailing list >>>>Jump-pilot-devel@lists.sourceforge.net >>>>https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >>>> >>>> >>>> >>>> >>>> >>>> >>>------------------------------------------------------------------------- >>>This SF.net email is sponsored by: Microsoft >>>Defy all challenges. Microsoft(R) Visual Studio 2005. >>>http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ >>>_______________________________________________ >>>Jump-pilot-devel mailing list >>>Jump-pilot-devel@lists.sourceforge.net >>>https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >>> >>> >>> >>> >>> >>> >>> >>------------------------------------------------------------------------- >>This SF.net email is sponsored by: Microsoft >>Defy all challenges. Microsoft(R) Visual Studio 2005. >>http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ >>_______________________________________________ >>Jump-pilot-devel mailing list >>Jump-pilot-devel@lists.sourceforge.net >>https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >> >> >> > > > >------------------------------------------------------------------------- >This SF.net email is sponsored by: Microsoft >Defy all challenges. Microsoft(R) Visual Studio 2005. >http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ >_______________________________________________ >Jump-pilot-devel mailing list >Jump-pilot-devel@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > > > ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
