AW: [GRASS-user] Project map

GRASS GRASS user
1

Hi!

I have another question concerning the projection of my vector layers.
I projected them by importing them from a mapset with geographic prj to a
mapset with lambert projection. V.out.ascii shows new coordinates which is
fine...

My question:
If I save my vector map as shp.-file for another GIS (ARCGIS in my case)
what projection does it use? My attribute table shows gg. Coordinates as in
GRASS. So do I have to project it another time?
(I also get a spatial reference alert back from the new GIS)

Thanks,

Steffi

-----Ursprüngliche Nachricht-----
Von: neteler.osgeo@gmail.com [mailto:neteler.osgeo@gmail.com] Im Auftrag von
Markus Neteler
Gesendet: Montag, 1. Dezember 2008 22:29
An: Stefanie Obmann
Betreff: Re: [GRASS-user] Project map

Hi,

genau das macht ja v.proj... um die *Koordinaten* zu sehen:

GRASS 6.4.svn (lwd_lambert):/tmp > v.out.ascii HYD
189372.298871|389304.88446131|960|1
199811.87693732|399440.72876217|870|2
205231.53218899|392987.94788857|1295|3
186523.46925359|404389.42735205|1090|4
197282.90012946|409257.52605648|810|5
...

Problem geloest?
Bei Linien und Flaechen muss noch format=standard dazu.

v.db.select zeigt ja nur die Attribute, die natuerlich nicht beruehrt werden
von v.proj (auch wenn Koordinaten darunter sind).

Gruesse,
Markus

On Mon, Dec 1, 2008 at 10:05 PM, Stefanie Obmann <stef_ob@gmx.at> wrote:

Hi,

I tried what you advised me to do and it works.
But what I really wanted to do is to get the map HYD into my location
"lwd_lambert" where all my coordinates should be projected to lambert
coordinates (unit: meters...) as the existing map in the location
lwd_lambert.
Isn't it possible?

Thanks a lot!
stef

-----Ursprüngliche Nachricht-----
Von: neteler.osgeo@gmail.com [mailto:neteler.osgeo@gmail.com] Im Auftrag

von

Markus Neteler
Gesendet: Montag, 1. Dezember 2008 21:42
An: Stefanie Obmann
Cc: GRASS user list
Betreff: Re: [GRASS-user] Project map

Stefanie,

(have received offlist the location)

I have tried with GRASS 6.4.svn on Linux, no problem:

GRASS 6.4.svn (lwd_lambert):/tmp > v.proj HYD loc=ggcoord map=stat_map
Building topology for vector map <HYD>...
Registering primitives...
117 primitives registered
117 vertices registered
Building areas...
100%
0 areas built
0 isles built
Attaching islands...
Attaching centroids...
100%
Number of nodes: 117
Number of primitives: 117
Number of points: 117
Number of lines: 0
Number of boundaries: 0
Number of centroids: 0
Number of areas: 0
Number of isles: 0

GRASS 6.4.svn (lwd_lambert):/tmp > v.db.select HYD
cat|x|y|hoehe|val
1|10.542778|47.369722|960|-1.2
[...]

When you run v.proj as indicated above, the v.db.select command
won't show all the attributes as here?

I suppose you use 6.3.0 Cygwin-GRASS, right (I forgot).

Is there any other Cygwin-GRASS who could make this test?

Markus

On Mon, Dec 1, 2008 at 7:50 PM, Stefanie Obmann <stef_ob@gmx.at> wrote:

Dear users,

what can I do to import and project my map with geographic projection in
another location of as in my case Austria lambert projection?

v.proj loses every information (the whole content of the attribute

table).

I would appreciate your help!

Thanks,

stef

--
Open Source Geospatial Foundation
http://www.osgeo.org/
http://www.grassbook.org/

2

On Wed, Mar 11, 2009 at 11:09 AM, Stefanie Obmann <stef_ob@gmx.at> wrote:

My question:
If I save my vector map as shp.-file for another GIS (ARCGIS in my case)
what projection does it use? My attribute table shows gg. Coordinates as in
GRASS. So do I have to project it another time?
(I also get a spatial reference alert back from the new GIS)

Thanks,

Steffi

When you save a shapefile in ArcGIS it will not necessarily carry
projection information. The shapefile only has projection information
if it has a .prj file with it or, if you explicitly set the projection
using ArcToolbox (Data management / projections and transformations /
DEFINE projection), which creates the .prj file

Cheers
Daniel

3

Daniel Victoria wrote:

  

My question:
If I save my vector map as shp.-file for another GIS (ARCGIS in my case)
what projection does it use? My attribute table shows gg. Coordinates as in
GRASS. So do I have to project it another time?
(I also get a spatial reference alert back from the new GIS)

Thanks,

Steffi

    


When you save a shapefile in ArcGIS it will not necessarily carry
projection information. The shapefile only has projection information
if it has a .prj file with it or, if you explicitly set the projection
using ArcToolbox (Data management / projections and transformations /
DEFINE projection), which creates the .prj file

In GRASS the module v.out.ogr has the ‘-e’ option to save an “ESRI-like” *.prj file.
Regards,
Micha

4

On 11/03/09 15:09, Stefanie Obmann wrote:

My question:
If I save my vector map as shp.-file for another GIS (ARCGIS in my case)
what projection does it use?

The projection of the location you export from, so in your case the Lambert.

My attribute table shows gg. Coordinates as in
GRASS. So do I have to project it another time?
(I also get a spatial reference alert back from the new GIS)

Your attribute table has nothing to do with the projection system your map is in. If the table contains columns with coordinates, these probably date from before the projection. If you want to replace these, use v.to.db upload=coor in the Lambert location.

Moritz