[GRASS-user] v.select output vector is empty

[Kevin Webb]

Greetings!

I am attempting to execute a "point-in-polygon" process on 2 vectors using
v.select and the output vector is empty, it contains no value/s.

When I create a map display of the 2 vectors I can clearly see the point
intersecting a polygon on the area layer, so it isn't an issue of 
no-intersecting
values between the two datasets.

The point vector was created using:
cat /home/kfw4/dev/grass_db/one_point.txt | v.in.ascii out=single_point 
fs=',' x=3 y=2 col='batch_id varchar(32),decimal_la double 
precision,decimal_lo double precision' --o


v.info and db.select show the correct imported value:

GRASS 6.4.svn (lat_lon):~ > v.info single_point
  +----------------------------------------------------------------------------+
  | Layer:           single_point
  | Mapset:          PERMANENT
  | Location:        lat_lon
  | Database:        /home/kfw4/dev/grass_db
  | Title:
  | Map scale:       1:1
  | Map format:      native
  | Name of creator: kfw4
  | Organization:
  |----------------------------------------------------------------------------
  |   Type of Map:  vector (level: 2)
  |
  |   Number of points:       1               Number of areas:      0
  |   Number of lines:        0               Number of islands:    0
  |   Number of boundaries:   0               Number of faces:      0
  |   Number of centroids:    0               Number of kernels:    0
  |
  |   Map is 3D:              No
  |   Number of dblinks:      1
  |
  |         Projection: Latitude-Longitude
  |               N:    34:06:59.1408N    S:    34:06:59.1408N
  |               E:    116:04:04.116W    W:    116:04:04.116W
  |
  |   Digitization threshold: 0
  |   Comments:
  |
  +----------------------------------------------------------------------------+

GRASS 6.4.svn (lat_lon):~ > db.select single_point
cat|batch_id|decimal_la|decimal_lo
1|BAT000000074|34.116428|-116.06781


The area vector was re-projected using v.proj:

  v.proj PREC0101 location=PREC0101 mapset=PERMANENT


GRASS 6.4.svn (lat_lon):~ > v.info PREC0101
  +----------------------------------------------------------------------------+
  | Layer:           PREC0101
  | Mapset:          PERMANENT
  | Location:        lat_lon
  | Database:        /home/kfw4/dev/grass_db
  | Title:
  | Map scale:       1:1
  | Map format:      native
  | Name of creator: kfw4
  | Organization:
  | Source date:     Wed Oct 29 09:15:47 2008
  |----------------------------------------------------------------------------
  |   Type of Map:  vector (level: 2)
  |
  |   Number of points:       0               Number of areas:      6720
  |   Number of lines:        0               Number of islands:    1212
  |   Number of boundaries:   13970           Number of faces:      0
  |   Number of centroids:    0               Number of kernels:    0
  |
  |   Map is 3D:              No
  |   Number of dblinks:      1
  |
  |         Projection: Latitude-Longitude
  |               N:  49:25:31.535591N    S:   24:27:48.66742N
  |               E:  66:54:50.339466W    W: 124:46:59.356755W
  |
  |   Digitization threshold: 0
  |   Comments:
  |
  +----------------------------------------------------------------------------+



Clearly, the single_point projection is contained by the PREC0101 
projection. (Clearly?)

Yet, v.select yields nothing.

GRASS 6.4.svn (lat_lon):~ >  v.select  ainput=single_point binput=PREC0101 
output=single_select op=overlap --overwrite --v
WARNING: Vector map <single_select> already exists and will be overwritten
Processing ainput lines ...
  100%
Processing ainput areas ...
Writing attributes ...
Layer 1
v.select complete.
Building topology for vector map <single_select>...
0 primitives registered
0 vertices registered
0 areas built
0 isles built
Attaching islands:
Attaching centroids: Topology was built
Number of nodes     :   0
Number of primitives:   0
Number of points    :   0
Number of lines     :   0
Number of boundaries:   0
Number of centroids :   0
Number of areas     :   0
Number of isles     :   0
GRASS 6.4.svn (lat_lon):~ > v.db.select -c single_select
GRASS 6.4.svn (lat_lon):~ > v.db.select -c single_select
GRASS 6.4.svn (lat_lon):~ >



Any suggestions?


Thank you.


KFW