Discrepancies between tcl/tk and wxpython PROJ_INFO files

[voncasec]

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

The summary at the end of the wxpython location wizard method says the proj.4 definition is:

+proj=utm, +zone=8, +a= 6378206.4000000004, +rf=294.9786982000, +dx=-22, +dy=157.0, +dz=176.0, +no_defs, +nadgrids=alaska

but if I run g.proj -j -f, I get the following output (which matches the PROJ_INFO file):

+proj=utm +no_defs +zone=8 +a=6378206.4 +rf=294.9786982 +to_meter=1

[neteler]

(prettified original report)

I just wonder if it is a problem what "nad27" isn't in the wxpython PROJ_INFO file

[cmbarton]

The wxPython GUI has a location wizard. The location wizard uses g.proj to create the location and the PROJ_INFO file.

The TclTk GUI does not have a location wizard. The location was created by ????. Maybe by g.projection??? an EPSG code??? Something else??? These may well make a different PROJ_INFO file.

The real question is are the locations different in terms of their projection parameters. What happens when you run g.region -gp?

What you see in the PROJ4 string in the location wizard is the string that goes into g.proj. It is based on what you picked.

A further question, what version of 6.4 are you using (when compiled) and for what platform?

Michael

[hamish]

please try again with the latest 6.4.0svn wx Location Wizard.

I'm pretty sure that this is fixed this now. (see #784, among others)

Hamish

[hamish]

(here the tcltk created region [runs g.setproj] was ok, but the wx location wizard was losing the datum/ellipsoid info)

[neteler]

comment from grass-dev:

On Mon, Jan 25, 2010 at 5:23 PM, Casey Vandenberg wrote:

I am pretty sure this has been fixed now too. I reported this a while back, and I have since updated GRASS with no issues related to projections.

Casey

So: closing, please reopen if still a problem.