[GRASS5] Grass Projection Parameters

Jeshua Lacock jeshua at SierraMaps.com
Thu Feb 14 00:53:26 EST 2002

On Wednesday, February 13, 2002, at 08:53 PM, Eric G. Miller wrote:

>> 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) ;)

Hello Eric,

Thanks for the pointers, that looks like the golden ticket.

So (all?) projections use either a custom datum OR ellipsoid. I assume 
that one of them must be supplied with all projections (minus XY)?

Thanks again,

Jeshua Lacock __________________________
Programmer/Owner            Phone:   760.935.4736
http://OpenOSX.com           Fax:        760.935.4845

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