[GRASS-dev] [GRASS GIS] #1851: Misalignment of an imported .asc raster

#1851: Misalignment of an imported .asc raster
-------------------------+--------------------------------------------------
Reporter: pcav | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 6.4.3
Component: Raster | Version: 6.4.2
Keywords: | Platform: Unspecified
      Cpu: Unspecified |
-------------------------+--------------------------------------------------
* import (-o) the .asc file from
https://www.dropbox.com/s/w60ywwddl3aj03h/cavallini.zip
* r.to.vect
(you can see the results of these operations in the location, in the zip
above)

Display raster and vector, either in GRASS or in QGIS (in this second you
can also load the original raster).

Results: the original raster and the derived vector align perfectly, the
imported raster shows shifts while zooming in and out. See attached
screenshots as an example.

Additionally, in qgis-dev I get errors querying the raster:
168 bytes expected but 3200000 byte were read from qgis.d.rast

Tested on 3 different machines (Debian Unstable, Ubuntu, Windows).

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1851&gt;
GRASS GIS <http://grass.osgeo.org>

#1851: Misalignment of an imported .asc raster
-------------------------+--------------------------------------------------
Reporter: pcav | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 6.4.3
Component: Raster | Version: 6.4.2
Keywords: | Platform: Unspecified
      Cpu: Unspecified |
-------------------------+--------------------------------------------------

Comment(by mmetz):

Replying to [ticket:1851 pcav]:
> * import (-o) the .asc file from
https://www.dropbox.com/s/w60ywwddl3aj03h/cavallini.zip
> * r.to.vect
> (you can see the results of these operations in the location, in the zip
above)
>
>
> Display raster and vector, either in GRASS or in QGIS (in this second
you can also load the original raster).

In the first (GRASS), you can also load the original raster via
r.external.
>
> Results: the original raster and the derived vector align perfectly, the
imported raster shows shifts while zooming in and out. See attached
screenshots as an example.

Looking at the metadata:

{{{
> g.region -g zoom=GR23B07 rast=GR23B07
n=4895155
s=4894780
w=1568780
e=1569043
nsres=1
ewres=1

> v.info -g map=G23B07vectV
north=4895155
south=4894780
east=1569043
west=1568780
}}}

The raster and the vector are exactly aligned, also when displayed with
GRASS wxGUI at different zoom levels, both with GRASS 6.4 and GRASS 7.

The attached screenshots 33.png and shot2.png are not made from GRASS
display with the location in cavallini.zip. Please try to display the
imported raster map and the derived vector map in the GRASS location in
cavallini.zip using GRASS.

>
> Additionally, in qgis-dev I get errors querying the raster:
> 168 bytes expected but 3200000 byte were read from qgis.d.rast

File a bug for qgis?
>
> Tested on 3 different machines (Debian Unstable, Ubuntu, Windows).

Unfortunately, the misalignment is not reproducible by others (at least 3
different people with different OS's and different GRASS versions).

Markus M

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1851#comment:1&gt;
GRASS GIS <http://grass.osgeo.org>

#1851: Misalignment of an imported .asc raster
--------------------------+-------------------------------------------------
  Reporter: pcav | Owner: grass-dev@…
      Type: defect | Status: closed
  Priority: normal | Milestone: 6.4.3
Component: Raster | Version: 6.4.2
Resolution: invalid | Keywords:
  Platform: Unspecified | Cpu: Unspecified
--------------------------+-------------------------------------------------
Changes (by pcav):

  * status: new => closed
  * resolution: => invalid

Comment:

OK, let's see if it's a pure qgis problem then.

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1851#comment:2&gt;
GRASS GIS <http://grass.osgeo.org>