[GRASS-user] Discrepancies between Location Wizard and Projection Values (WXPython vs TCLTK)

[Paul Kelly]

On Thu, 4 Jun 2009, Casey Vandenberg wrote:

> Hi everyone,
>
> I have been noticing some discrepancies in the PROJ_INFO files that are 
> created using Grass6.4 RC4 between the projection values option in the tcltk 
> interface and the location wizard option using the wxpython interface.
>
> For example, inputting the projection info:
>
> Coordinate System=UTM
> Datum=Nad27 - T04 (Transformation Parameters for Alaska)
> Ellipse: Clark66
> Zone=8
>
> I get the following PROJ_INFO files created.
>
> tcltk interface results:
>
> name: UTM
> datum: nad27
> nadgrids: alaska
> proj: utm
> ellps: clark66
> a: 6378206.4000000004
> es: 0.0067686580
> f: 294.9786982000
> zone: 8
>
> wxpython results:
>
> name: Universe Transverse Mercator
> proj: utm
> ellps: clark66
> zone: 8
> no_defs: defined

They are exactly equivalent except that the wxpython one is missing the 
datum information (adding the line "nadgrids: alaska" would fix that). So 
the Tcl/Tk one is actually correct.

Paul