[GRASS5] Grass Projection Parameters
Eric G. Miller
egm2 at jps.net
Wed Feb 13 23:53:51 EST 2002
On Wed, Feb 13, 2002 at 08:26:25PM -0800, Jeshua Lacock wrote:
> We are developing a product called MacGrass that is based on Grass as a
> powerful engine and MacGrass as an elegant front end while also adding
> capabilities, features and ease of use.
> I am working on the Projection GUI and I was wondering if there is way
> to find out what projections and Ellipsoids require which parameters.
> It was not immediately apparent by looking at documentation or the
> source code in src/libes/proj or by grep'ing elsewhere.
> See <http://OpenOSX.com/MacGrassAlpha.jpg>
> Is there a way to find or generate a list that shows which parameters
> are required/supported by each of the 121 projections?
> For instance Albers Equal Area use False Easting and Northing, etc.
> that say UTM does not. Another example is UTM requires a zone and so
Have a look at grass/src/libes/gis/geo_init.c Do your user's a favor
though, and don't offer *both* datum and ellipsoid (make it either or)
as a datum defines the ellipsoid (still need it in PROJ_INFO). This
behavior in g.setproj is almost irritating enough for me to go and
fix it (that, and the state plane crap) ;)
Eric G. Miller <egm2 at jps.net>
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