[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:
>  Hello, 
> 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 
> forth. 

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>

More information about the grass-dev mailing list