Hey Martin, Thanks for your reply, which I'll work through slowly.
I've come to realize that while geotools relies almost entirely on the EPSG database, that database does not have the major global projections. (That makes sense since they are interested in finding oil which ultimately involves digging a small but long hole in a particular place). Geotools, then, will have to generate its own authority system for the global projections (say Peeters equal area or others). Is there any plan for this work? Does anyone have recommendations/strategies for this? I think that geotools should definitely hard code the mathematical limits of the projections which it has implemented. There is no reason that a user should not be able to hand geotools a global data set and ask for a Mercator projection. There could be warnings that the data exceeds (ever so slightly) the maximum extent allowed, we could even throw exceptions but it should be easy for a user to do since it's a perfectly reasonable operation. I imagine there are similar situations in other projections that i would also expect to have "just work". On Sun, 2006-08-13 at 10:37 +0200, Martin Desruisseaux wrote: > Latest ISO 19111 revision (not yet reflected into GeoAPI interfaces) added a > field in > CoordinateSystemAxis, This addition is cool but does not really impact the CRS issue since they are distinct. As you well understand, the axis range of longitude is [-90\deg,+90\deg] while the Mercator projection is defined only for (-90\deg,+90\deg) and for a realistic implementation, we would have to avoid coming too close to the extremes, so probably [-89,89] would make sense depending both on the computational limits of the library (i.e. going to 89.99999999 is theoretically legit, probably computationally problematic, and realistically of little interest to anyone). Let's make geotools robust and accurate---easy to get results when these are possible but with loud indications that what is being done may not make sense and why (e.g. trying to project data within the maximum extent but outside the area of validity). --adrian ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Geotools-gt2-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
