Hi Milton; A month or so ago we went over how to generate an equal area projection (either generate the WKT using Albers Conic; or do something similar programatically). There are a number of "AUTO" projections defined in GeoTools (they take the form "AUTO:<CODE>,<lat>,<lon>"). But I am not aware if any of them are equal area ... perhaps you could look.
People do donate additional projections; perhaps you would be interested in donating one of the ones you mention? The documentation and the use of BC Albers in examples is mostly my fault as that is where I was working. Let us know how you go; I think an "AUTO" projection that used Albers Conic would be great. Jody On 14/07/2010, at 1:41 AM, Milton Jonathan wrote: > Hello > > We have a simple issue down here: we want to compute the area of an > arbitrary polygonal feature. > > The straightforward way I thought about was to simply convert that > geometry to an equal-area projection, and then let JTS Geometry.getArea > do the rest. > > However... I was surprised that I couldn't find a single equal-area > projection in GeoTools that is available globally (say the user wants to > compute the area of Russia, or of Antarctica). From what I saw, > something like the Mollweide or Sinusoidal projections would do the job, > but they don't seem to be currently implemented in GeoTools. > > Going around the documentation, e-mail lists, etc. my impression is that > the only available equal-area projection is the Albers Conic Equal-Area. > However, it's not clear to me how I should play around with the standard > parallel parameters (ok, would need to study it a little), but more than > the that I'm really not sure how this would behave for features that > cross the equator. > > Any help appreciated! > > Cheers > Milton > > -- > > Milton Jonathan > Grupo GIS e Meio Ambiente > Tecgraf/PUC-Rio > Tel: +55-21-3527-2502 > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by Sprint > What will you do first with EVO, the first 4G phone? > Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first > _______________________________________________ > Geotools-gt2-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users ------------------------------------------------------------------------------ This SF.net email is sponsored by Sprint What will you do first with EVO, the first 4G phone? Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first _______________________________________________ Geotools-gt2-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
