Opened 10 years ago

Closed 10 years ago

#631 closed defect (fixed)

Discrepancies between tcl/tk and wxpython PROJ_INFO files

Reported by: voncasec Owned by: grass-dev@…
Priority: normal Milestone: 6.4.0
Component: Default Version: unspecified
Keywords: Projections, wxpython, tcltk Cc:
CPU: Unspecified Platform: Unspecified

Description (last modified by neteler)

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

Change History (5)

comment:1 Changed 10 years ago by neteler

Description: modified (diff)

(prettified original report)

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

comment:2 Changed 10 years ago by 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

comment:3 Changed 10 years ago by 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

comment:4 Changed 10 years ago by hamish

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

comment:5 Changed 10 years ago by neteler

Resolution: fixed
Status: newclosed

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.

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