Projections request...

[Morten Hulden]

Hi Eric,

you can add support for false easting&northing for Alber's Equal Area in
GRASS5beta by editing the file src/libes/gis/geo_init.c. On line 35, just
after the last TABLE[AEA] definition, add the following lines:

	TABLE[AEA][X0].ask = 1;
	TABLE[AEA][X0].def_exists = 1;
	TABLE[AEA][X0].deflt = 0.0;

	TABLE[AEA][Y0].ask = 1;
	TABLE[AEA][Y0].def_exists = 1;
	TABLE[AEA][Y0].deflt = 0.0;

Then recompile.

regards
Morten Hulden


On Sun, 13 Aug 2000, Eric G . Miller wrote:

> Several months ago, I asked about False Northing/Eastings for the Albers
> Equal Area Projection.  GRASS currently doesn't allow the specification
> of these items for this projection.  Recently I was contacted by another
> person who read my previous posting about this subject -- wondering if I
> had a solution.
> 
> Anyway, a number of state agencies in California have standardised on an
> Albers Equal Area Projection that has a false northing.  There is quite
> a bit of data available in this projection.  Unfortunately, there's no
> clean way to get this data into GRASS at the moment.  I know the proj4
> library supports this feature; so, I'm wondering if it would be possible
> to implement it?  I've been searching through the GRASS code base, but
> am not familiar enough with it to know how all the projection code ties
> together.  I know there are many other things on the TODO list, but
> perhaps someone familiar with the projection code could point me in the
> right direction(s)?
> 
> Thanks.
>