Hi
I managed to solve it:
v.in.ogr dsn=./shp/ layer=fireHistory output=fireHistory
v.category input=fireHistory output=tmpFire
v.db.addtable map=tmpFire table=tmpFire_2 layer=2 columns='num,int'
v.to.db map=tmpFire layer=2 qlayer=1 option=query col=num
qcol='count(*)' type=centroid
finally I can export it to a raster layer:
v.to.rast input=tmpFire layer=2 output=mf use=attr column=num --overwrite
Could the code on the website
http://grass.osgeo.org/screenshots/vector.php please be updated, as it
is not working under grass 6.3 and less commands are necessary?
Is there a WIKI to which I could upload the code?
Thanks for your help,
Rainer
On Tue, Jun 24, 2008 at 10:32 AM, Rainer M Krug <r.m.krug@gmail.com> wrote:
On Tue, Jun 24, 2008 at 9:57 AM, Hamish <hamish_b@yahoo.com> wrote:
Is there another way of getting the number of overlapping features
per cell?Hi,
maybe this helps- you can try Radim's example from the vector screenshots page. (see GRASS 6.0 "Overlapping polygons" section)
http://grass.osgeo.org/screenshots/vector.php
Yes, funny place for tutorial material, but it demos some functionality.
Thanks Hamish - I found that one alredy, but it does not work:
OK - her is what I did:
v.category input=fire_p output=fire_c type=centroid option=add --o <<-- option field=2 does not exist any more?
WARNING: Vector map <fire_c> already exists and will be overwritten
Building topology ...
3901 primitives registered
Building areas: 100%
1220 areas built
54 isles built
Attaching islands: 100%
Attaching centroids: 100%
Topology was built.
Number of nodes : 2735
Number of primitives: 3901
Number of points : 0
Number of lines : 0
Number of boundaries: 2746
Number of centroids : 1155
Number of areas : 1220
Number of isles : 54
Number of areas without centroid : 65
[Raster MASK present]echo "create table fire_c_2 (id int, num int)" | db.execute
v.db.connect map=fire_c driver=dbf layer=2 table=fire_c_2 key=id -o
The table <fire_c_2> is now part of vector map <fire_c> and may be deleted
or overwritten by GRASS modules
[Raster MASK present]> v.to.db map=fire_c layer=2 option=cat col=id <<-- option col1=
changed to col=
Updating database...
100%
7 categories read from map
0 records selected from table
0 categories read from map exist in selection from table
6 categories read from map don't exist in selection from table
6 records updated/inserted
0 update/insert errors
[Raster MASK present]> v.to.db map=fire_c layer=2 qlayer=1 option=query column=num
qcolumn="count(*)" type=centroid <<-- option col1= changed to column=
qcol= to qcolumn=
Reading data from the map...
100%
Querying database...
DBMI-DBF driver error:
SQL parser error:
in statement:
SELECT count(*) FROM ...
Error in db_open_select_cursor()I guess this is a problem with the dbf database? Is there any way of
solving this in dbf?Rainer
Hamish
--
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation
Biology, UCT), Dipl. Phys. (Germany)Plant Conservation Unit
Department of Botany
University of Cape Town
Rondebosch 7701
South Africa
--
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation
Biology, UCT), Dipl. Phys. (Germany)
Plant Conservation Unit
Department of Botany
University of Cape Town
Rondebosch 7701
South Africa
