[GRASS-user] help with testing the location wizard for the upcoming release

[Nikos Alexandris]

Hamish wrote:
> Hi, this is a general call for help.

Hi,

> if anyone/everyone is able to help test, we have made some fixes
> to the wxGUI new location wizard since 6.4.3rc3, which really
> need to be tested well before the final release. We think all is
> ok now, but a messed up location projection definition and ruin
> everything downstream in the location, so it's an important
> thing to be totally sure of.
 
> since there are so many projections and datums and ways to
> select them, it's pretty hard to test for "working/not working"
> as we usally could do. Please try throwing your local odd-ball
> CRS at it and see what happens. (check all the way through to
> 'g.proj -p' and 'g.proj -j' in the final location session. make
> sure it does what you'd expect it to do.
 
> specifically how datum transforms are handled, and CRSs without
> a specificed datum or specified datum terms; usuing all methods
> of defining the projection system. see trac issues #1849 and
> #1967 for further details.

[..]


Below, maybe not exactly something that helps the testing process... but, 
anyway here it goes:  I guess it is not possible to follow the good old text-
based way in building a custom coordinate system.

For example, like

#####################################################################
grass64 -text

[snip]

LOCATION:   hgrs87_test______________  (enter list for a list of locations)
MAPSET:     PERMANENT________________  (or mapsets within a location)

DATABASE: 
/geo/grassdb/testing_________________________________________________



           AFTER COMPLETING ALL ANSWERS, HIT <ESC><ENTER> TO CONTINUE
                            (OR <Ctrl-C> TO CANCEL)

#####################################################################

Would you like to create location <hgrs87_test> ? (y/n) [y]

#####################################################################

To create a new LOCATION, you will need the following information:

1. The coordinate system for the database
        x,y (for imagery and other unreferenced data)
        Latitude-Longitude
        UTM
        Other Projection
2. The zone for the UTM database
   and all the necessary parameters for projections other than
   Latitude-Longitude, x,y, and UTM
3. The coordinates of the area to become the default region
   and the grid resolution of this region
4. A short, one-line description or title for the location

Do you have all this information? (y/n) [y]

#####################################################################

Please specify the coordinate system for location <hgrs87_test>

A   x,y
B   Latitude-Longitude
C   UTM
D   Other Projection
RETURN to cancel

> D

#####################################################################

Other Projection coordinate system? (y/n) [y]

#####################################################################

Please enter a one line description for location <hgrs87_test>

> Hellenic Geodetic Reference System 1987
=====================================================
Hellenic Geodetic Reference System 1987
=====================================================
ok? (y/n) [y] 


Please specify projection name
Enter 'list' for the list of available projections
Hit RETURN to cancel request
>tmerc
Do you wish to specify a geodetic datum for this location?(y/n) [y] 

Please specify datum name
Enter 'list' for the list of available datums
or 'custom' if you wish to enter custom parameters
Hit RETURN to cancel request
>custom

Please specify ellipsoid name
Enter 'list' for the list of available ellipsoids
Hit RETURN to cancel request
>grs80

Please specify datum transformation parameters in PROJ.4 syntax. Examples:
        towgs84=dx,dy,dz        (3-parameter transformation)
        towgs84=dx,dy,dz,rx,ry,rz,m     (7-parameter transformation)
        nadgrids=alaska (Tables-based grid-shifting transformation)
Hit RETURN to cancel request
>towgs84=-199.87,74.79,246.62,0,0,0,0
Parameters to be used are:
"towgs84=-199.87,74.79,246.62,0,0,0,0"
Is this correct?(y/n) [y]

#####################################################################

Enter Scale Factor at the Central Meridian  [1.0000000000]: 0.9996

    Enter Central Parallel (23N) :0

    Enter Central Meridian (96W) :24

Enter False Easting  [0.0000000000]: 500000

Enter False Northing  [0.0000000000]: 
Enter plural form of units [meters]:

#####################################################################



...which will define a Location

--%<---
g.proj -p

-PROJ_INFO-------------------------------------------------
name       : Transverse Mercator
towgs84    : -199.87,74.79,246.62,0,0,0,0
proj       : tmerc
ellps      : grs80
a          : 6378137.0000000000
es         : 0.0066943800
f          : 298.2572221010
k_0        : 0.9996000000
lat_0      : 0.0000000000
lon_0      : 24.0000000000
x_0        : 500000.0000000000
y_0        : 0.0000000000
-PROJ_UNITS------------------------------------------------
unit       : meter
units      : meters
meters     : 1.0
--->%--


All is ok using the correct epsg code (e.g. 2100).  However, what about 
replicating the above process with the new Wizard?

Thanks, Nikos