[GRASS-user] Site in Polygon Query
jarekj at amu.edu.pl
Wed May 23 07:55:59 EDT 2007
Martin Wegmann napisał(a):
>On Wednesday, 23. May 2007 12:29:41 Michael Malicky wrote:
>>I am using GRASS for some time now, mainly for plotting distribution maps
>>of plants and animals. Now a user came up with a different request:
>>We have a map consisting of polygons and another one with sites. We need a
>>query to filter all polygons that include at least one site. Is there a
>>special command for this or a script ? Any help is welcome.
>just an idea:
>v.to.rast of polygons and sites (use=val)
>r.mapcalc "output = if(map_sum > 1,1,null())"
Another simple idea
v.to.rast of polygons with unique cats as raster value
add column to points vector named 'poly_col'
v.what.rast on new raster
echo "count(*), poly_col, FROM your_point_table_name GROUP BY poly_col" |db.execute
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